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TABLE OF CONTENTS Subject
Page
Introduction Section I . Design WhyGaskets Are Used ,
Effecting Gasket
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a Seal
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...
...,
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Seating
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... ...
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Table 1 - Gasket Materials and Contact Facings Table 2 - EffectiveGasket Width ,..., Table 3 - Gasket Seating Surface Finishes Forces Acting on a Gasketed Joint Bolt Load Formulas , Notation Symbols and Definitions Table 4 - MaximumSg Values ,
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...
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2
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,
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3 ,
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3 4 5
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8 9 9 10 11
"..,
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"
,..,
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"
,..,
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Heat Exchanger Gaskets - Standard Shape Index Spiral Wound Gaskets , ,
SizingSpiralWoundGaskets Flange Surface Finishes. , Available Spiral Seal Styles
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13 ,
,..,
",..,
Bolt Torque
Sequence.
TorqueValues
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Manway Problems? . Manway Application Information Other Problem Areas
Section
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,
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23
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,.29
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,...,..,..,.30 , 31 ...;.."" , 32
33
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,..,
Chemical Resistance Chart - Grafoil@ Circumferences and Areas of Circles Torque Required to Produce Bolt Stress Bolting Materials - Stress Table 1 Bolting Data for Standard Flanges
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28
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,..,
ASME Section VIII, Div. I - Design Consideration for Bolted Flange Connections Chemical Resistance Chart - Gasket Metals Maximum Service Temperatures - Gasket Metals Chemical Resistance Chart - Vegetable Fiber Sheet
SoftSheetGasketDimensions
,..,26 27
,...
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IV - Appendix
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23 26
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,...
Sheet ,
22
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15 15 17 20 21 22
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,
,
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Trouble Shooting Leaking Joints
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11 11
,
'...,
,...,...,...
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Section III . Installation Installation and Maintenance Tips Gasket Installation Procedures
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,
'-"
.." ,..,
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MetallicGasket Materials Metal Gaskets ,.., , Solid Metal Gaskets , MetalJacketed Gaskets Metal Clad and Solid Metal Heat Exchanger Gaskets ,
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6-7
8 , ...,...
Example Sample Gasket Calculation - Steam Service Section II. Selection , "
Selecting.the ProperGasketMaterial Non-Metallic GasketMaterials
3
,...,..,..3
,..,..
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33 "... 35 37 37 ,..
38
,..,
"
40
41 , "
45 46 47
INTRODUCTION The cost of leaky joints in industry today is staggering. Out-of-pocket costs run into billions of dollars annually in lost production, waste of energy, loss of product and, most recently, impact on the environment. These problems are increasing, not decreasing. It behooves all of us to consolidate our knowledge and experience to solve or at least minimize these problems. This publication is being produced because we, as gasket manufacturers and suppliers, are constantly called upon to solve sealing problems after the fact. Too often we find insufficient time and attention has been given to: . proper design of flanged joint . installation procedures and . selection of the optimum gasket material required to solve a particular sealing problem. We will endeavor to outline in this publication those areas we believe to be essential in a properly designed, installed and m"aintainedgasketed joint. We believe most people involved with the design, installation, and maintenance of gasketed joints realize that no such thing as "zero" leakage can be achieved. Whether or not a joint is "tight" depends on the sophistication of the methods used to measure leakage. In certain applications the degree of leakage may be perfectly acceptable if one drop of water per minute is noted at the gasketed joint. Other requirements are that no bubbles would be observed if the gasketed joint was subjected to an air or gas test underwater and a still more stringent inspection would require passing a mass spectrometer test. The rigidity of the test method would be determined by: . the hazard of the material being confined . loss of critical materials in a process flow . impact on the environment should a particular fluid escape into the atmosphere . danger of fire or of personal injury All of these factors dictate proper attention must be given to: . design of flange joints or closures . proper selection of gasket type proper gasket material . proper installation procedures Care in these areas will ensure that the best technology goes into the total package and will minimize operating costs, pollution of the environment and hazards to employees and the general public.
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2
SECTION I WHY GASKETS ARE USED '--"
Gaskets are used to create a static seal between two stationary members of a mechanical assembly and to maintain that seal under operating conditions which may vary dependent upon changes in pressures and temperatures. If it were possible to have perfectly mated flanges and if it were possible to maintain an intimate contact of these perfectly mated flanges throughout the extremes of operating conditions, a gasket would not be required. This is virtually an impossibility either because of the size of the vessel and/or the flanges the difficulty in maintaining such extremely smooth flange finishes during handling and assembly . corrosion and erosion of the flange surfaces during operations. As a consequence, relatively inexpensive gaskets are used to provide the sealing element in these mechanical assemblies. In most cases, the gasket provides a seal by external forces flowing the gasket material into the imperfections between the mating surfaces. It follows then that in a properly designed gasket closure, three major considerations must be taken into account in order for a satisfactory seal to be achieved. . Sufficient force must be available to initially seat the gasket. Stating this another way, adequate means must be provided to flow the gasket into the imperfections in the gasket seating surfaces. Sufficient forces must be available to maintain a residualstress on the gasket under operating conditions to ensure that the gasket will be in intimate contact with the gasket seating surfaces to prevent blow-by or leakage. The selection of the gasket material must be such that it will withstand the pressures exerted against the gasket, satisfactorily resist the entire temperature range to which the closure will be exposed and withstand corrosive attack of the confined medium.
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DESIGN . By heat, such as in the case of sealing a bell and
spigot joint on cast iron pipe by means of molten lead. Note, however, that after the molten lead is poured, it is tamped into place using a tamping tool and a hammer. Gasket lip expansion. This is a phenomenon that would occur due to edge swelling when the gasket would be affected by confined fluid, as in the case of elastomeric compounds affected by the confined fluids, such as solvents, causing the gasket material to swell and increase the interaction of the gasket against the flange faces. Generally, gaskets are called upon to effect a seal across the faces of contact with the flanges. Permeation of the media through the body of the gasket is also a possibility depending on material, confined media, and acceptable leakage rate.
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EFFECTING A SEAL A seal is affected by compressing the gasket material and causing it to flow into the imperfections on the gasket seating surfaces so that intimate contact is made between the gasket and the gasket seating surfaces preventing the escape of the confined fluid. Basically there are four different methods that may be used either singly or incombination to achieve this unbroken barrier. Compression (Figure 1). This is by far the most common method of effecting a seal on a flange joint and the compression force is normally applied by bolting. Attrition (Figure 2). Attrition is a combination of a dragging action combined with compression such as in a spark plug gasket where the spark plug is turned down on a gasket that is both compressed and screwed into the flange.
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GASKET SEATING There are two major factors to be considered with regard to gasket seating. The first is the gasket material itself. 'The ASME Unfired Pressure Vessel Code Section VIII, Division 1 defines minimum design seating stresses for a variety of gasket materials. These design seating stresses range from zero psi for so-called self-sealing gasket types such as low durometer elastomers and O-rings to 26,000 psi to properly seat solid flat metal gaskets. Between these two extremes there are a multitude of materials available to the designer enabling him to make a selection based upon the specific operating conditions under investigation. Table No.1 indicates the more popular types of gaskets covered by ASME Unfired Pressure Vessel Code. (can't on page 6)
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TABLE UA-49.1 GASKET MATERIALS AND CONTACT FACINGS "-" Gasket Factors (m) for Operating Conditions and Minimum Design Seating Stress (y) NOTE: This table gives a list of many commonly used gasket materials and contact facings with suggested design values of m and y that have generally proved satisfactory in actual service when using effective gasket seating width b given in Table UA-49.2. The design values and other details given in this table are suggested only and are not mandatory.
Gasket factor m
Gasket material Self-Energizing types 0 Rings. Metallic. Elastomer other gasket types considered as self-sealing Elastomerswithout fabric.
0
Min. design seating stress y (psi)
0 200
Elastomers with cotton fabric insertion
1.25
400
Vegetable fiber
1.75
1100
3.00
10000
Solid flat metal
Ring joint
-
-
1 (a, b, c, d)
Soft Aluminum Soft copper or brass Iron or soft steel Monel or 4-6% chrome Stainless steels
2.50 2.75 3.00 3.25 ..-
..
3.50_-
2.75 3.00
2900 3700 4500 5500 J..-- 6500 3700 4500
3.25
5500
3.50 3.75 3.25
6500 7600 5500
Soft copper or brass Iron or soft steel Monel 4-6% chrome Stainless steels Soft aluminum Soft copper or brass Iron or soft steel Monel or 4-6% chrome Stainless steels Soft aluminum Soft copper or brass Iron or soft steel Monel or 4-6°/ chrome Stainless steels
3.50 3.75 3.50 3.75 3.75 3.25 3.50 3.75 3.75 4.25
6500 7600 8000 9000 9000
Iron or soft steel Monel or 4-6% chrome Stainless steels
Iron or soft steel Monel or 4-6% chrome Stainless steels
4.00 4.75 5.50 6.00
5500 6500 7600 9000 10100 8800 13000 18000 21800
6.50
26000
5.50 6.00 6.50
18000 21800 26000
II
r}
Monel
Softaluminum
Grooved metal
-
---
Carbon Stainless or
Soft aluminum
Flat metal jacketed with nonmetallic filler
Use column
4, 5
Soft copper or brass Corruga1ed metal
Use facing sketch
0
0.50 1.00
Corrugated metal, double jacketed with nonmetallic filler
Sketches and notes
-
Below 75 Shore Durometer 75 or higher Shore Durometer
Spiral-wound metal, with nonmetallic filler
Refer to Table UA-49.2
1 (a, b)
,
I
\< \..-.-.
(
1 (a, b, c, d)
1a, 1b, 1c*,
1d*,2*
.25 1 (a, b, c, d) 2,3
-.--.II
1 (a, b, c, d) 2,3,4,5
I
6
*The surface of a gasket having a lap should be against the smooth surface of the facing and not against the nubbin. Reprinted
with permission
of ASME
"-"
4
TABLE UA~49.2 EFFECTIVE GASKET WIDTH
'-'
-
Basic Gasket Seating Width, b Column I I Column II
Facing Sketch
1a
~~~~ggerated '/."c>
;;;;;;~~;;' N' 1b*
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;:c;/,;;»///0J0~~;;;;
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N 2
N 2
w ; T; (W : N max)
w ; T; (w : N ma1
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1c
S';v;c;
-
w<.N
---:1
~~~N 1d*
;>;;~
-
~ " ';;'E1J~"';;i8S 2
w<.N
r:
1/64" Nubbin !~, "~';;>;~ 1
w+N 4
w;;~ 2
w +3N 8
-LNj.' 3
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/"r---1/64" Nubbin:
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w;;~
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N 4
3N 8
3N 8
7N 16
N 4
3N 8
2
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6 w 8
Effective Gasket Seating Width, aba b = boowhen bo b =
~2
.
~ 114in.
when bo > 114in.
Location of Gasket Load Reaction HG
HG G--.I--hG--1 °F~'C~O~!~~ --~ b 1---
'-'
G ---1-- hG !
I
---I,
Face
I
NOTE: The gasket factors listed only apply to flanged joints in which the gasket is contained entirely within the inner edges of the bolt holes.
*Where serrations do not exceed 1/64 in. depth and 1/32 in. width spacing, sketches 1b and 1d shall be used. Reprinted with permission
of ASME
5
(con't from page 3) The second major factor to take into consideration must be the surface finish of the gasket seating surface. As a general rule, it is necessary to have a relatively rough gasket seating surface for elastomeric and PTFE gaskets on the order of magnitude of 500 microinches. Solid metal gaskets normally require a surface finish not rougher than 63 microinches. Semi-metallic gaskets such as spiralwound fall between these two general types. The reason for the difference is that with non-metallic gaskets such as rubber, there must be sufficient roughness on the gasket seating surfaces to bite into the gasket thereby preventing excessive extrusion and increasing resistance to gasket blowout. In the case of solid metal gaskets, extremely high unit loads are required to flow the gasket into imperfections on the gasket seating surfaces. This requires that the gasket seating surfaces be as smooth
as possible to ensure an effective seal. Spiral-wound gaskets, which have become extremely popular in the last fifteen to twenty years, do require some surface roughness to prevent excessive radial slippage of the gasketunder compression.The characteristicsof the type of gasket being used dictate the proper flange surface finish that must be taken into consideration by the flange designer and there is no such thing as a single optimum gasket surfacefinish for all types of gaskets.The problem of the proper finish for gasket seating surface is further complicated by the type of the flange design. For example a totally enclosed facing such as tongue and groove will permit the use of a much smoother gasket seating surface than can be tolerated with a raised face. Table3 includes recommendationsfor normal finishes for the various types of gaskets.
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TABLE 3 GASKET SEATING SURFACE FINISHES Flange Surface Finish "- AARH
Gasket Descrigtion Flat -
Non-Metallic
Flat -
Metallic'
SEE NOTE 1
Corrugated metal
Corrugated metal with soft filler
Metal jacketed gaskets
NOTE: This table gives a list of suggested surface finishes that have generally proven satisfactory in actual service. They are suggested only and not mandatory; however, they are based upon the best cross-section of successful design experience currently available.
250-500
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63
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63
125
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63-80
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TABLE 3
GasketDescription \",.;
Metaljacketed gaskets (cant.)
-
GASKET
SEATING
-
SURFACE
FINISHES
Gasket Cross-Section
CONT. Flange Surface
Finish /.L"- AARH 63-80
63
Solid metal
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-----------
'-"
'-,,-- ',
>-. ,,--"-'"
y
Hollow metal
"',
Spiral
wound
.......... Note
-
.. SEE NOTE 2
'
32 - -')
125 - 250
Solid metal washer type gaskets require extremely high seating stresses to seal. This usually necessitates a bolt area to gaskel
area greater than a ratio of 2: 1. If this is not possible, it is preferred to use a profiled or serrated gasket to achieve the necessal seating load on the gasket. Note @ - Refer to page 23 for more details on flange surface finishes for spiral wound gaskets.
I
FORCES ACTING ON A GASKETED JOINT
gasKet seating surfaces regardless of operating conditions. Initial compression force must be great enough to compensate for the total hydrostatic end force that would be present during operating conditions. It must be sufficient to maintain a residual load on the gasket/flange interface. From a practical standpoint, residual gasket load must be "X" times internal pressure if a tight joint is to be maintained. This unknown quantity "X" is what is known as the "m" factor in the ASME unfired pressure vessel code and will vary depending upon the type of gasket being used. Actually the "m" value is the ratio of residual unit stress (bolt load minus hydrostatic end force) on gasket (psi) to internal pressure of the system. The larger the number used for "m," the more conservative the flange design would be, and the more assurance the designer has of obtaining a tight joint.
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BOLT LOAD HYDROSTATIC END FORCE GASKET
INTERNAL OR BLOW OUT PRESSURE
Forces acting on a gasket joint (Figure 1)
. THE INTERNAL PRESSURE: These are the forces continually try. .
. .
ing to unseal a gasketed joint by exerting pressure against the gasket (blowout pressure) and against the flanges holding the gasket in place (hydrostatic end force). See Figure 1. THE FLANGE LOAD: The total force compressing the gasket to create a seal, Le., the effective pressure resulting from the bolt loading. TEMPERATURE: Temperaturecreates thermo-mechanical effects, expanding or contracting the metals, affecting the gasket material by promoting "creep relaxation" which is a permanent strain or relaxation quality of many soft materials under stress. The effect of certain confined fluids may become increasingly degrading as temperature rises and attack upon organic gasket materials is substantially greater than at the ambient temperatures (about 75°F). As a rule, the higher the temperature, the more critical becomes the selection of the proper gasket. MEDIUM: The liquid or gas against which the gasket is to seal. GENERAL CONDITIONS: The type of flange, the flange surfaces, the type of bolt material, the spacing and tightness of the bolts, etc.
Each of these factors require consideration before an effective gasket material is finally chosen. However, the proper gasket may .often be rejected because failure occurred due to a poorly cleaned flange face, or improper bolting-up practice. These details require careful attention, but if complied with will help eliminate gasket blowout or failure.
BOLT LOAD FORMULAS* The ASME Unfired Pressure Vessel Code, Section VIII, Division 1 defines the initial bolt load required to seat a gasket sufficiently as: Wm2 = 1TbGy
The required operating bolt load must be at least sufficient, under the most severe operating conditions, to contain the hydrostatic end force and, in addition, to maintain a residual compression load on the gasketthat is sufficient to assure a tight joint. ASME defines this bolt load as: Wm1= ~G2P 4
'-'
+ 2b1TGmP
After WM1and Wm2are calculated, then the minimum required bolt area Am is determined: -
A
Wm1
m1 - s:There are three principal forces acting on any gasketed joint. They are: Bolt load and/or other means of applying the initial compressive load that flows the gasket material into surface imperfections to form a seal. The hydrostatic end force, that tends to separate flanges wh~mthe system is pressurized. Internal pressure acting on the portion of the gasket exposed to internal pressure, tending to blow the gasket out of the joint and/or to bypass the gasket under operating conditions. There are other shock forces that may be created due to sudden changes in temperature and pressure. Creep relaxation is another factor that may come into the picture. Figure 1 indicates the three primary forces acting upon a gasketed joint which we will consider for this discussion. The initial compression force applied to a joint must serve several purposes. It must be sufficient to initially seat the gasket and flow the gasket into the imperfections on the
Am2
.
. .
.
= Wm2 Sa
Am
= Am1 if Am1
;; Am2
OR
Am
= Am2 if Am2
;;;; Am1
Bolts are then selected so that the actual bolt area Ab is equal to or greater than Am Ab = (Number of Bolts) x (Minimum Cross-Sectional Area of Bolt in Square Inches) Ab ~ Am The maximum unit load Sg(max)on th~ gasket bearing surface is equal to the total maximum bolt load in
pounds divided by the actual sealing area of the gasket ~Sa
Sg(max)-
~ [(aD - 0.125)2 - (ID)2] AbSa Sg(max)= -.I! [(OD)2 - (ID)2] 4
8
\
in square inches.
Spiral Wound -J Gaskets
Ail Other Types of -J Gaskets
v
NOTATION SYMBOLS AND DEFINITIONS When bo ;; % in., G = mean diameter of gasket contact face, inches. When bo > % in., G = outside diameter of gasket contact face less 2b, inches.
Except as noted, the symbols and definitions below are those given in Appendix II of the 1977 ASME Boiler and Pressure Vessel Code, Section VIII.
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Ab
= actual total cross-sectional area of bolts at root of thread or section of least diameter under stress, square inches.
Am = total required cross-sectional area of bolts, taken as the greater of Am1or Am2' square inches. Am1 = total cross-sectional area of bolts at root of thread or section of least diameter under stress, required for the operating conditions. Am2 = total cross-sectional area of bolts at root of thread or section of least diameter under stress, required for gasket seating.
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b
= effective gasket or joint-contact-surface seating width, inches. Table 2
bo
= basic gasket seating width, inches. Table 2.
G
= diameter at location of gasket load reaction. Table 2.
m
= gasket factor. Table 1.
N
= width, in inches, used to determine the basic gasket seating width bo, based upon the possible contact width of the gasket. Table 2.
P
=
Sa
= allowable bolt stress at ambient temperature, pounds per square inch.
Sb
= allowable bolt stress at operating temperature, pounds per square inch.
Sg
= Actual unit load at the gasket bearing surface, pounds per square inch.
design pressure, pounds per square inch.
Wm1 = required pounds.
bolt load for operating
conditions,
Wm2 = minimum required bolt load for gasket seating, pounds. y
= gasket or joint-contact-surface unit seating load, minimum design seating stress, PSI Table 1 pounds per square inch.
*The Pressure Vessel Research Council (PVRC) has developed a program to better identify loads based on gasket "sealability". Thus, new design factors are anticipated to appear in upcoming revisions of the ASME Boiler and Pressure Vessel Code. (Lamons is a sponsor of PVRC research).
,
9
SAMPLE GASKET APPLICATION PROBLEM
1. From Table 1, Page 4 m=3 y = 10,000
For assistance with a particular gasket problem contact Lamons Sales Department, or a technical representative.
2. From page 22, "Sizing Spiral Wound Gaskets Confined on 1.0. and 0.0.", the gaskets should have an I.D. of 22" and an 0.0. of 23". Since the facing is groove to flat face, the gasket thickness must be .175"*. From Table 2, Page 5 N = 1/2" = 0.500" b = 0.250" b0 = 0.250" G = 22.5"
EXAMPLE CONDITIONS: A designer wants a gasket recommendation for a special application sealing steam at 600 psi and 500°F.
3. From formula on page 8. Wm2 = nbGy = 3.14 x 0.250" x 22.5" x 10,000 PSI = 176,625 Ibs. Wm1 = 11 4 G2P + 2bnGmP
CONDITIONS: Design pressure - 600 psi Test pressure - 900 psi Design temperature - 500°F Process material - steam Flange details -
Wm1(Design) = 0.785 x (22.5")2 x 600 PSI + 2 x 0.250" x 3.14 x 22.5" x 3 x 600 PSI = 238,444 + 63,585 . Wm1 (Test)
-Av-
231/16"a.D.
~
'\;--
2115/16" LD.
1/6'~ :+
Details of Flange
Bolting - 24 - 11/8"- 8 thds. Bolt Material - ASTM A193 - B7 Flange Material- ASTM A312 Type 316 S.S. Allowable bolt stress @Ambient Temperature, according to Stress Table 1, Page 45 is only 20,000 PSI; however, to prevent leakage under hydrotest it is decided to tighten bolting to 30,000 PSI (See Note at bottom of Stress Table 1, Page 45; Appendix S, Page 32; and "Note", Page 27. Allowable Stress @500°F - 20,000 1 Appendices Page 45.
PSI(see Stress Table
Analysis The pressure-temperature conditions indicate a metallic type gasket should be used. The conditions appear to be suitable for a spiral wound gasket. The flange material, 316 S.S., is compatible with the steam environment @500°F. Therefore, the logical choice for the metal in the gasket is 316 S.S. Since Grafoil@is also compatible with the environment (see page 40), it is selected as the filler material.
10
J
= 302,029 Ibs. = 0.785 x (22.5")2 x 900 PSI + 2 x 0.250" x 3.14 x 22.5" x 3 x 900 PSI = 357,666 + 95,378 = 453,043 Ibs.
From Table on Page 42 and definition of Ab, page 8 Ab = 24 x 0.728 = 17.472 sq. in. Bolt load @ Test Condition: 30,000 x 17.472 = 524,160 Ibs. Bolt Load @ Design Condition: 20,000 x 17,472 = 349,440 Ibs. It is apparent adequate bolting is available. Minimum required bolt loading for gasket seating (Wm2)is 176,625 Ibs. Available load for gasket seating is 524,160 Ibs. Minimum required bolt at design conditions is 302,029 Ibs. and available load at design conditions is 349,440 Ibs. Note: required bolt load at test conditions is 453,043 Ibs. and available bolt load at test conditions is 524,160 Ibs. Since a positive stop is designed into the flange, i.e. groove to flat, no additional precautions are necessary. Any forces in excess of the force required to compress the gasket will be transmitted to the flange faces and gasket crushing cannot occur. From the above analysis, it appears our original assumption is correct and the recommendation would be: SpiraSeal Type W Gasket - 316 S.S./Grafoil@ 22" 10 x 23" 00 x 0.175" Thick
J
*The optimum compressed thickness for a .175" thick spiral wound gasket is .130" :t .005" (See page 23). The 1/8" groove depth is within this range.
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SECTION II - SELECTION '-"
SELECTING THE PROPER GASKET MATERIAL The optimum gasket material would have the following characteristics. It would have the chemical resistance of PTFE, the heat resistance of graphite, the strength of steel, require a zero seating stress such as soft rubber and be inexpensive. Obviously there is no known gasket material that has all these characteristics and each material has certain limitations that restrict its use. It is possible to overcome limitations partially by several methods such as including the use of reinforcing inserts, combining it with other materials, varying the construction or density, or by designing the joint itself to overcome some of the limitations. Obviously, mechanical factors are important in the design of the joint but the primary selection of a gasket material is influenced by three factors, the temperature of the fluid or gas to be contained, the pressure of the fluid or gas to be contained, the corrosive characteristics of the fluid or gas to be contained. Charts included in the appendix indicate some very general recommendations for non-metallic and metallic materials against various corrosive media. It should be pointed out that these charts are general recommendations and there are many additional factors that
. . .
can influence the corrosion resistance of a particular material at operating conditions. Some of these would include Concentration of the corrosive agent. (Full strength solutions are not necessarily more corrosive than those of dilute proportions and, of course, the reverse is also true.) The purity of a corrosive agent. For example, dissolved oxygen in otherwise pure water may cause rapid oxidation of steam generation equipment at high temperatures. The temperature of the corrosive agent. In general, higher temperatures of corrosive agents will accelerate corrosive attack. As a consequence, it is often necessary to "field-test" materials for resistance to corrosion under normal operating conditions to determine if the material selected will have the required resistance to corrosion.
.
.
.
TYPES OF GASKETS For the purposes of this bulletin, gaskets will be separated into two broad categories, non-metallic and metallic gaskets. Of the two types, non-metallic gaskets are by far the most widely used. This discussion will cover the various types of non-metallic materials, general application data and temperature limitations.
NON-METALLIC GASKET MATERIALS NATURAL ~
RUBBER
Natural rubber has good resistance to mild acids and alkalies, salts and chlorine solutions. It has poor resistance to oils and solvents and is not recommended for use with ozone. Itstemperature range is very limited and is suitable only for use from -70°F to 200°F. SBR (STYRENE-BUTADIENE) SBR is a synthetic rubber that has excellent abrasion resistance and has good resistance to weak organic acids, alcohols, moderate chemicals and ketones. It is not good in ozone, strong acids, fats, oils, greases and most hydrocarbons. Its temperature limitations are approximately -65°F to 250°F. CR (CIU.OROPRENE) (NEOPRENE) Chloroprene is a synthetic rubber that is suitable for use against moderate acids, alkalies and salt solutions. It has good resistance to commercial oils and fuels. It is very poor against strong oxidizing acids, aromatic and chlorinated hydrocarbons. Its temperature range would be from approximately -60°F to 250°F.
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BUNA-N RUBBER (NITRILE, NBR) Buna-N is a synthetic rubber that has good resistance to oils and solvents, aromatic and aliphatic hydrocarbons, petroleum oils and gasolines over a wide range of temperature. It also has good resistance to caustics and salts but only fair acid resistance. It is poor in strong oxidizing agents, chlorinated hydrocarbons, ketones and esters. It is suitable over a temperature range of approximately -60°F to 250°F.
carbons and strong acids. It is not suitable for use against amines, esters, ketones or steam. Its normal temperature range would be between -15°F and 450°F. CIILOROSULFONATED POLYETHELENE (HYPALON) This material has good acid, alkali and salt resistance. It resists weathering, sunlight, ozone, oils and commercial fuels such as diesel and kerosene. It is not good in aromatics or chlorinated hydrocarbons and has poor resistance against chromic acid and nitric acid. Its normal temperature range would be between -50°F and 275°F. SILICONES Silicone rubbers have good resistance to hot air. They are unaffected by sunlight and ozone. They are not, however, suitable for use against steam, aliphatic and aromatic hydrocarbons. The temperature range would be between -65°F to 500°F. EPDM (ETHYLENE MONOMER
PROPYLENE),
This synthetic material has good resistance to strong acids, alkalies, salts and chlorine solutions. It is not suitable for use in oils, solvents or aromatic hydrocarbons. Its temperature range would be between - 70°F and 350°F.
FLUOROCARBON (VITON) Fluorocarbon elastomer has good resistance to oils, fuel, chlorinated solvents, aliphatic and aromatic hydro11
.
GRAFOIL@ This is an all graphite material containing no resins or inorganic fillers. It is available with or without a metal insertion, and in adhesive-back tape form for pipe gaskets over 24 inches in diameter. Grafoil has outstanding resistance to corrosion against a wide variety of acids, alkalies and salt solutions, organic compounds, and heat transfer fluids, even at high temperatures. It does not melt, but does sublimate at temperatures over 6000°F. Its use against strong oxidizing agents at elevated temperatures should be investigated very carefully. In addition to being used as a gasket, Grafoil makes an excellent packing material and is also used as a filler material in spiral-wound gaskets.
CERAMIC FIBER Ceramic fiber is available in sheet or blanket form and makes an excellent gasket material for hot air duct work with low pressures and light flanges. It is satisfactory for service up to approximately 2000°F. Ceramic material is also used as a filler material in spiral-wound gaskets.
the filler dimensions. Clearance is required between the 1.0. of the filler and the envelope lO. The Gasket 0.0. normally rests within the bolt hole circle and the 1.0. is approximately equal to the nominal 1.0. of pipe. Available in sizes to a maximum 0.0. of 24".
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Milled Type
Milled envelopes are machined from cylinder stock. The jacket is machined from the 0.0. to within approximately 1/32" its 1.0.The jacket's 1.0. fits flush with pipe bore and its 0.0. nests within the bolts. Available in sizes up to a maximum 0.0. of 24". Milled envelopes are more expensive than slit type since considerably more material is lost in machining. Formed Tape Type
PLASTICS Of all the plastics, PTFE(polytetrafluoroethylene)has emerged as the most common plastic gasket material PTFE's outstanding properties include resistance to temperature extremes from -140°F to 450°F (for virgin material). PTFEis highly resistantto chemicals, solvents, caustics and acids except free fluorine and alkali metals. It has a very low surface energy and does not adhere to the flanges. PTFEgaskets can be supplied in a variety of forms either as virgin material or reprocessed material and also with a variety of filler material such as glass,"carbon, molybdenum disulfite, etc. The principal advantage in adding fillers to PTFEis to inhibit cold flow or creep relaxation.
PTFE ENVELOPE GASKETS
Large diameter (over 12" N.P.S.) and irregularly shaped envelopes are formed from tape and heat sealed to produce a continuous jacket construction. Filler
Materials
The more popular fillers for envelope gaskets are: Rubber sheet Compressed non-asbestos . Corrugated metal inserts . Sandwich constructionscombining some of the above On vacuum applications, double envelopes are frequently used where two jackets are overlapped to protect the 0.0. as well as the I.D. They can be slit, milled or formed tape types.
. .
~
Envelope gaskets utilizing PTFEjacket have become popular for use in severely corrosive services because of their low minimum seating stresses,excellent creep resistance,high deformability and choice of a variety of ~
filler materialsto assureoptimumperformanceon any specific application. Fillerssuch as corrugated metaland rubber sheets are available. There are three basic designs of envelopes:
Sli t Type
J Slit envelopes are sliced from cylinders and split from the outside diameter to within approximately 1/16" of the inside diameter. The bearing surface is determined by 12
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COMPRESSED NON-ASBESTOS SHEETING Early efforts to replace asbestos resulted in the introduction and testing of compressed non-asbestosproducts in the 1970's. Many of these products have seen extensiveuse since that period howeverthere havebeen enough problems to warrant careful consideration in choosing a replacement material for compressed asbestos. Most manufacturers of non-asbestos sheet materials use synthetic fibers, like Kevlar@,in conjunction with an elastomeric binder. The elastomeric binder makes up a larger percentage of this sheet and thereby becomes a more important consideration when deterNote: On page 8, the term "pressure temperature conditions" was used indicating that these values are used to help determine the types of material and construction to be used in a gasket. A "Rule of Thumb" guide for the selection of gasket materials has evolved over the years. This value is arrived at by multiplying operating pressure times operating temperature. MATERIAL Rubber VegetableFiber Solid Fluorocarbon
MAXIMUMP xT 15,000 40,000 75,000
MAXIMUM* TEMPERATURE OF MATERIALS, of 250 250 500
METALLIC
..........
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mining applications. @
VEGETABLE
316 STAINLESS STEEL An 18-12 Chromium-Nickel steel with approximately 2 % of Molybdenum added to the straight 18-8 alloy which increases its strength at elevated temperatures and results in somewhat improved corrosion resistance. Has the highest creep strength at elevated temperatures of any conventionalstainless type. Not suitable for extended service within the carbide precipitation range
FIBER
SHEET
Vegetable fiber sheet is a tough pliable gasket material manufactured by paper making techniques utilizing plant fibers and a glue-glycerine impregnation. It is widely used for sealing petroleum products, gases and a wide variety of solvents. Its maximum temperature limit is 250° F.If a more compressible material is required, a combination cork-fiber sheet is available.The cork-fiber sheet has the same maximum temperature limitation as the vegetable fiber sheet.
*Temperature limits of gasketing materials are not absolute figures. Materials within any category may vary depending upon a manufacturer's processing techniques, grades and types of raw materials used, etc, In addition, flange design and application peculiarities may influence the temperature limit of a material to a greater or fesser degree.
GASKET
CARBON STEEL Commercial quality sheet steel with an upper temperature limit of approximately1OOO°F.,particularly if conditions are oxidizing. Not suitable for handling crude acids or aqueoussolutionsof salts in the neutral or acid range. A high rate of failure may be expected in hot water service if the material is highly stressed. Concentrated acids and most alkalies have little or no action on iron and steel gaskets which are used regularly for such services. Brinell hardness is approximately 120. 304 STAINLESS STEEL An 18-8(Chromium18-20%, Nickel 8-10%) Stainless with a maximum recommendedworking temperature of 1400°F. At least 80% of applications for non-corrosive services can use Type304 Stainless in the temperature range of - 320°F. to 1O00°F.Excellent corrosion resistance to a wide variety of chemicals. Subject to stress corrosion cracking and to intergranular corrosion at temperatures between 800°F. to 1500°F. in presence of certain media for prolonged periods of time. Brinell hardness is approximately 160. 304L STAINLESS STEEL Carbon content maintained at a maximum of .03% Recommendedmaximumworkingtemperatureof 1400°F F. Same excellent corrosion resistance as Type 304. This low carbon content tends to reduce the precipitation of carbides along grain boundaries. Lesssubject to intergranular corrosion than Type304. Brinell hardness is about 140
Kevlar is a registered trademark of E.!. DuPontCo.
MATERIALS
of 800° to 1650°F.when corrosive conditions are severe. Recommendedmaximum working temperature of 1400° F. Brinell hardness is approximately 160. 316-L STAINLESS STEEL Continous maxiumum temperature range of 1400°1500° F. Carbon content held at a maximum of .03% . Subject to a lesser degree of stress corrosion cracking and also to intergranular corrosion than Type 304. Brinell hardness is about 140. 321 STAINLESS STEEL An 18-10Chromium-Nickelsteel with a Titanium addition. Type321 stainless has the same characteristics as Type 347. The recommended working temperature is 1400° to 1500°F. and in some instances 1600°F. Brinell hardness is about 150. 347 STAINLESS STEEL An 18-10 Chromium-Nickel steel with the addition of Columbium. Not as subject to intergranularcorrosion as is Type304. Is subject to stress corrosion. Recommended workingtemperatureof 14000-1500°F.and in some instances to 1700°F.Brinell hardnessis approximately160. 410 STAINLESS STEEL A 12% Chromium steel with a maximum temperature range of 1200°F. to 1300°F. Used for applications requiring good resistance to scaling at elevated temperatures. Is not recommended for use where severe corrosion is encountered but is still very useful for some chemical applications. May be used where dampness, alone or coupled with chemical pollution, causes steel to fail quickly. Brinell hardness is around 155. 502/501 4-6% Chromium and 1/2 Molybdenumalloyedfor mild corrosive resistance and elevated service. Maximum working temperature is 1200°F. and has a Brinell hardness of around 130. If severe corrosion is anticipated, a better grade of stainless steel would probably be a better choice. Becomes extremely hard when welded. 13
ADMIRALTY Arsenical Admiralty 443 has 71% Copper, 28% Zinc, 1% Tin and trace amounts of Arsenic. High corrosive resistance, holds up extremely well against salt and brackish waters, and water containing sulfides. Recommended maximum working temperature of 500° F. Ideal for carrying corrosive cooling waters at relatively high temperatures. Brinell hardness is about 64.
ALLOY 20 45% Iron, 24% Nickel, 20% Chromium, and small amounts of Molybdenum and Copper. Maximum temperature range of 1400°-1500°F.Developed specifically for applications requiring resistance to corrosion by sulphuric acid. Brinell hardness is about 160. ALUMINUM
Alloy 1100is commerciallypure (99% minimum). Its excellent corrosion resistance and workability makes it ideal for double jacketed gaskets. The Brinell hardness is approximately 35. For solid gaskets, stronger alloys like 5052 and 3003 are used. Maximum continuous service temperature of 800° F. BRASS Yellow brass 268 has 66% Copper and 34% Zinc. Offers excellent to good corrosion resistance in most environments, but is not suitable for such materials as acetic acid, acetylene, ammonia, and salt. Maximum recommended temperature limit of 500° F.Brinell hardness is 58. COPPER Nearly pure copper with trace amounts of silver added to increase its working temperature. Recommended maximum continuous working temperature of 5000 F. Brinell hardness is about 80.
varying concentrations as well as boiling nitric acid up to 70% concentration. Good resistance to hydrochloric acid and sulphuric acid. Excellent resistance to stress corrosion cracking. Brinell hardness is about 210.
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INCONEL 600@ Recommendedworking temperatures of 2000°F. and is some instances 2150°F. Is a nickelbase alloy containing 77% Nickel, 15% Chromiumand 7% Iron. Excellent high temperature strength. Frequently used to overcome the problem of stress corrosion. Has excellent mechanical properties at the cryogenic temperature range. Brinell hardness is about 150. INCOLOY 800@ 32.5% Nickel, 46% Iron, 21% Chromium. Resistant to elevated temperatures, oxidation, and carburization. Recommended maximum temperature of 1600° F. Brinell hardness is about 150. MONEL@ Maximum temperature range of 1500° F. Contains 67% Nickel and 30% Copper. Excellent resistance to most acids and alkalies, except strong oxidizing acids. Subject to stress corrosion cracking when exposed to fluorosilic acid, mercuric chloride and mercury, and should not be used with these media. With PTFE (Polytetrafluoroethylene), it is widely used for hydrofluoric acid service. Brinell hardness is about 120. NICKEL 200@ Recommended maximum working temperature is 14000 F. and even higher under controlled conditions. Corrosion resistance makes it useful in caustic alkalies and where resistance in structural applications to corrosion is a prime consideration. Does not have the allaround excellent resistance of Monel. Brinell hardness is about 110.
CUPRO NICKEL Contains 69% Copper, 30% Nickel, and small amounts of Manganese and Iron. Designed to handle high stresses, it finds its greatest application in areas where high temperatures and pressures combined with high velocity and destructive turbulence would rapidly deteriorate many less resistant alloys. Maximum recommended temperature limit of 500° F.Brinell hardness is about 70.
PHOSPHOR BRONZE 90-95% Copper, 5-10% Tin, and trace amounts of phosphorus. Maximum temperature range of 500° F. Excellent cold working capacity. Limited to low temperature steam applications. Excellent corrosion resistance, but not suitable for acetylene, ammonia, chromic acid, mercury, and potassium cyanide. Brinell hardness is approximately 65.
HASTELLOY B@ 26-30% Molybdenum, 62% Nickel, and 4-6% Iron. Maximum temperature range of 2000° F. Resistant to hot, concentrated hydrochloric acid. Also resists the corrosive effects of wet hydrogen chlorine gas, sulphuric and phosphoric acids and reducing salt solutions. Useful for high temperature strength. Brinell hardness is approximately 230.
TITANIUM Maximum temperature range of 2000° F. Excellent corrosion resistance even at high temperatures. Known as the "Best solution" to chloride ion attack. Resistant to nitric acid in a wide range of temperatures and concentrations. Most alkaline solutions have little if any effect upon it. Outstanding in oxidizing environments. Brinell hardness is about 215.
HASTELLOY C-276@ 16-18%Molybdenum, 13-17.5%Chromium, 3.7-5.3% Tungsten, 4.5-7% Iron, and the balance is Nickel. Maximum temperature range of 2000° F.Very good in handling corrosives. High resistanceto cold nitric acid of 14
Note Maximum temperature ratings are based upon hot air constant temperatures. The presence of contaminating fluids and cyclic conditions may drastically affect the maximum temperature range.
v
J
MATERIAL HARDNESS CONVERSION SCALE Brinell hardness figures are approximate guides only. Most materials ordered by Lamons are specified "dead soft"; however, different thicknesses and different heats of the same material will vary in hardness. Brinell 3000 Kg. Load 241 210 183 163 146 134 122
Rockwell "B" 100
~
95 90 85 80 75 70 65 60 55 50 40
108 95 89 83 75
30 20 10
67 62 57
METAL GASKETS Metallic gaskets are available in many forms including, . solid metal gaskets that require very smooth, plain surface finishes and high clamping forces in order to seal, combinations with soft fillers such as doublejacketed and spiral-wound that can tolerate greater surface roughness and will seat with lesser compressive forces, and light cross section gaskets that are self-sealing and require minimum clamping forces for effective sealing. In all cases, however,careful attention must be given to machining details of the flanges and sizing of the gaskets.
KAMMPROFILE KAMMPROTM
The design features of the grooves in combination with the special properties of the facing materials result in optimal performance and consistency. The simultaneous action of high compressibilityfacing material on the outside of the grooved metal in combination with limited penetration of the tips of the solid metal core enhance the interactionof the two materials. This allows each to perform individually to their optimum. Lamons manufacturesKammpro in a wide range of metals and alloys to exact specifications.
PROFILE GASKETS
.
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.
SOLID METAL GASKETS PLAIN FLAT METAL GASKETS
"'"
Flat metal gaskets are best suited for applications such as valve bonnets, ammonia fittings, heat exchangers, hydraulic presses, tongue-and-groove joints. They can be used when compressibility is not required to compensate for flange surface finish, warpage or misalignment and where sufficient clamping force is available to seat the particular metal selected. They must be sealed by the flow of the gasket metal into the imperfections on the gasket seating surfaces of the flange. This requires heavy compressive forces. The hardness of gasket metal must be less than the hardness of the flanges to prevent damage to the gasket seating surface of the flange. Flat metal gaskets are relatively inexpensive to produce and can be made of virtually any material that is available in sheet form. Size limitation is normally restricted to the sheet size. Larger gaskets can be fabricated by welding.
Profile type gaskets offer the desirable qualities of plain washer types and the added advantage of a reduced contact area provided by the V-shaped surface. It is used when a solid metal gasket is required because of pressure or temperature or because of the highly corrosive effect of the fluid to be contained and also when bolting is not sufficient to seat a flat washer.
A PROFILE GASKET WITH A METAL JACKET
It flange conditions require a profile type gasket, but flange protection is required as well, the profile gasket may be supplied with either a single-jacketed or a double-jacketed shield. This will provide protection for the flanges and will minimize damage to the flange faces due to the profile surface. NOTE: Without exception all of the solid metal gaskets require a very fine surface finish on the flanges. A flange with a flange surface roughness of 63 microinches or smoother is desired. Under no circumstances should the surface finish exceed 125 microinches. In addition, radial gouges or scores would be almost impossible to seal using solid metal gaskets.
15
ROUND CROSS SECTION, SOLID METAL GASKETS
LENS TYPE GASKET "-.J
Round cross section solid metal gaskets are used on specifically designed flanges grooved or othewise faced to accurately locate the gasket during assembly. These gaskets seal by a line contact which provides an initial high seating stress at low bolt loads. This makes an ideal gasket for low pressures. The more common materials used for this type of gasket would be aluminum, copper, soft iron or steel, Monel@,nickel, and 300 series stainless steels. They are fabricated from wire formed to size and welded. The weld is then polished to the exact wire diameter.
A lens type gasket is a line contact seal for use in high pressure piping systems and in pressure vessel heads. The lens cross section is a spherical gasket surface and requires special machining on the flanges. These gaskets will seat with a small bolt load since the contact area is very small and gasket seating pressures are very high. Normally the gasket material should be softer than the flange. In ordering lens gaskets, complete drawings and material specifications must be supplied.
DELTA GASKET API RING JOINT GASKETS
API ring joint gaskets come in two basic types, an oval cross section and an octagonal cross section. These basic shapes are used in pressures up to 5,000 psi. The dimensions are standardized and require specially grooved flanges. The octagonal cross section has a higher sealing efficiency than the oval and would be the 'preferred gasket. However, only the oval cross section can be used in the old type round bottom groove, The newer flat bottom groove design will accept either the oval or the octagonal cross section. The sealing surfaces on the ring joint grooves must be smoothly finished to 63 microinches and be free of objectionable ridges, tool or chatter marks. They seal by an initial line contact or a wedging action as the compressive forces are applied. The hardness of the ring should always be less than the hardness of the flanges. Dimensions for ring joint gaskets and grooves are covered in ASME B16.20, API6A, and ASME/ANSI B16.5.
BX AND RX RING GASKETS
The BX ring gasket differs from the standard oval or octagonal shape in that it is square in cross section and tapers in each corner. They can only be used in API 6BX flanges. RX ring gaskets are similar is shape to the standard octagonal ring joint gasket but their cross section is designed to take advantage of the contained fluid pressure in effecting a seal. They are both made to API 6A. 16
A delta gasket is a pressure actuated gasket used primarily on pressure vessels and valve bonnets at very high pressures in excess of 5000 psi. As with the lens gasket, complete drawings and material specifications must be supplied. Internal pressure forces the gasket material to expand when the pressure forces tend to separate the flanges. Extremely smooth surface finishes of 63 microinches or smoother are required when using this type of gasket.
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BRIDGEMAN GASKET
The Bridgeman gasket is a pressure activated gasket for use on pressure vessel heads and valve bonnets for pressures of 1500 psi and above. The cross section of the gasket is such that internal pressure acting against the ring forces it against the containing surface making a self-energized seal. Bridgeman gaskets are frequently silver plated or lead plated to provide a softer surface and minimize the force required to flow the gasket metal into the flange surface.
MISCELLANEOUS METAL GASKETS
-..J In addition to the commonly used, above-listed gaskets, there are specialty items available that, in specific applications, can provide a very effective seal. These
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miscellaneous gaskets would include hollow metal 0rings, C-seals and V-seals, so-called because their cross section is essentially the same as the letters C & V. The hollow metal O-rings are available vented for high pressure applications and pressure filled for high temperature applications. They can be obtained with various platings in order to enhance their sealing abilities and to meet specific applications requirements. C-seals can be used either for vacuum applications or for high pressure applications. C-seals are self-energized gaskets requiring specific attention be paid to the design of the grooves to contain the gasket, and smooth surface finishes are a must. For large quantity applications, the C~seal can be a relatively low cost gasket. For small quahtity appllcati,ens; the cost can be rather high because of initial t§§IIA~ fequirements. V-seals are similar t8 the Q~§eale}(cept fcJr tAefa81that they are essEHltiailyFnael1lAe§§ffiI39neht8 Wl1iehmakes
~a§~etfather high: flley al§§ require verY flhe sldftae8tIAI§h@§ and specially §e=
the cost df the.ih~IVifJuai
commercially, this particular gasket style is very popular. It must be remembered that the primary seal against leakage, using a double-jacketed gasket, is the metal inner lap where the gasket is thickest before being compressed and densest when compressed. This particular section flows, effecting the seal. As a consequence the entire inner lap must be under compression. Frequently the outer lap is not under compression and does not aid in the sealing of the gasket. On most heat exchanger applications the outer lap is also under compression, providing a secondary seal. The intermediate part of a double-jacketed gasket does very little to effect the sealing capability of the gasket. In some cases nubbins are provided on heat exchanger designs to provide an intermediate seal. This nubbin is normally 1/64" high by 1/8"'wide. Experience has indicated, however, that there is little advantage to this particular design. The primary seal is still dependent on the inner lap of the gasket abing the brute work and the secondary seal, when applicable, would be provided by the outer lap.
signee] gfbo\!es ta effectiVely seal. All these specialty items do reqLilre initial consultation witH the manufacturer in order to determine the practicability and the economics involved. METAL
JACKETED
CONSTRUCTION GASKETS
,......
GASKETS
OF JACKETED
Lamons jacketed gaskets are normally supplied with a non-asbestoshigh temperaturefiller.The standard filler is normally sufficientfor applications up to 900°F. Other softfillers are availablefor higher temperaturesor special applications including Grafoil~ Standard metals used to make jacketed gaskets, regardless of the type, are aluminum, copper, the various brasses,soft steel, nickel, Monel@,Inconel@and stainless steel types 304, 316, 321,
347,410,502. Obviouslythe choice of the metal used for the jacketed part of the gasket would depend upon the corrosive conditions being encountered.
Always install double jacketed the nubbin.
gasket with smooth
side toward
DOUBLE-JACKETED CORRUGATED GASKETS DOUBLE-JACKETED GASKET
"""
Double-jacketed gaskets are probably the most commonly used style of gasket in heat exchanger applications. They are available in virtually any material that is commercially availablein 26-gauge sheet. They are also extensivelyused in standard flanges where the service is not critical and at temperatures beyond which a soft gasket such as rubber can be used. Since most doublejacketed gaskets are custom made, there is virtually no limit to the size, shape or configuration in which these gaskets can be made. This particular type of gasket is very versatile and can be used in a myriad of applications. Since the size and shape are not a problem and since most materials can be obtained
The double-jacketed corrugated gasket is an improvement on a plain jacketed gasket in that the corrugations on the gasket will provide an additional labyrinth seal. It also provides the advantage of reducing the contact area of the gasket, enhancing its compressive characteristics. A double-jacketed corrugated gasket still relies on the primary seal on the inner lap. Note: Double-jacketed gaskets are sometimes used with a very-light coating of gasket cement or lubricant which will assist in flowing the metal portion of the gasket into the tool marks on the flange seating surface. (Cont.)
17
They are made by encasing a soft filler on one face, both edges and a portion of the other face with a metal. The majority of applications for single-jacketed gaskets are normally 1/4" or less in radial width. This type of gasket is widely used in air tool applications and engine applications where space is limited, gasket seating surfaces are narrow and relatively low compressive forces are available for seating the gasket. For applica,tions in excess of 1/4", a double-jacketed gasket or doublejacketed corrugated gasket is normally recommended. Most single-jacketed gaskets are supplied with copper as the jacketing material, however, other materials are available.
v
SINGLE-J ACKETED OVERLAP
._"...t~~
.m.aa:1I't~.JJ;lJMS:tAd
When using a gasket compound or lubricant it is important to remember to use only a very light coating. Excessive amounts of lubricant or compound may cause total gasket failure if the joint is exposed to high temperature and/or pressure.
J4d\ii)g~R2.. In the single-jacketed overlap construction the maximum flange width is approximately 1/4". This type of gasket is used when total enclosure of the soft filler material is required and when the flange width makes it impractical to use a double-jacketed gasket.
FRENCH TYPE GASKETS
French type gaskets are available in a one-piece jacketed construction for narrow radial widths not exceeding 1/4" and in two- and three-piece constructions, as shown in the sketches, for wider applications. This type of gasket can also be used with the jacket on the external edge of the gasket when the application requires the outer edge of the gasket to be exposed to fluid pressure. The most widely used French type gaskets are fabricated using a copper sheath. The doublejacketed construction is preferred over the French or single-jacketed construction, where practical, since it provides a totally shea.thed gasket with none of the soft filler exposed.
DOUBLE-JACKETED DOUBLE-SHELL GASKET
v
The double-jacketed, double-shelled gasket is similar to the double-jacketed gasket except that instead of using a shell and a washer, two shells are used in the fabrication of the gasket. It has the advantage of a double lap at both the 1.0. and the 0.0. of the gasket, adding greater stability to the gasket. The construction will withstand higher compressive loads. Double-shell gaskets are normally restricted to use in high pressure applications. Its temperature limitations depend upon the type of metal and filler used in construction.
MODIFIED FRENCH TYPE
illttboo,;. Iit¥Js~~l
SINGLEJACKETED GASKET
Single-jacketed gaskets are normally used for relatively narrow applications similar to the French type. 18
This particulartype of gasketis normally used with very light flanges on duct work handling hot gases. Its construction consists of two French type shields welded together with a Cerafeltfiller materialon either side of the metal. Metal thickness is normally 26 gauge, rolled on the 1.0. to act as a shield.
v
DOUBLE-JACKETED CORRUGATED GASKET WITH A CORRUGATED METAL FILLER
~
CORRUGATED AND CORRUGATED INLAID GASKETS STYLE
eaD10JJ.$.'~!S~ At temperatures in excess of the range of 900°F to 10000 F where the standard soft filler is normally not recommended, a double-jacketed corrugated metal gasket with a corrugated metal filler is frequently used. This construction has all the advantages of the doublejacketed corrugated metal gasket and, in addition, since the filler is normally the same material as the gasket itself, il1@ bJ~pertemperature limit would be determined by the metal
BeihgU§et30 this tYpeof
gasket, depending
upon metal selected, makes an excellent heat exchanger gasket for high pressure, high temperature applications. As in the case of double-jacketed metal gaskets and double-jacketedcorrugated metal §askets, tHe primary seal would be the inner lap 5f metal; the sec8RtJarysea! ,would be the outer lap 6f metal and some degree of labyrinth sealing can be achieved with the corrugations.
- SIZING
METAL
JACKETED
Lamons corrugated gaskets, style 360, are economical for use on relatively low pressure applications that require low bolt loads for gasket seating. Because of the corrugations and thin metal thicknesses (.010" to .031"), relatively light bolt forces are required to flow the gasket materials at the points of contact with the flange. Required bolt loads are substantially less tHan the solia metal types such as flat metal, profile 5F §errateai faBricated of the same material. The corrugations proviae resilier1t8, the amount of which depends on their ~itth, depth, and thickness of material. A superior sealing surface can be created using .015 thick layers of Grafoil@ tape applied to each face, style 360G.
GASKETS-
The following sizings and tolerances are not mandatory but are suggested values based upon experience. a ,...,...
GASKETS
Gasket 1.0.
Gasket 0.0.
GASKETS
ON O.D. AND
CONFINED
Groove 1.0.
=
=
LD.
+ 1/16"
Groove 0.0. -1/16"
CONFINED
ON O.D. ONLY
Gasket 1.0. = Bore + minimum 1/8" Gasket 0.0.
GASKETS
= Recess 0.0.
UNCONFINED
-
1/16"
ON O.D. AND I.D.
Gasket 1.0. = Bore + minimum 1/8" Gasket 0.0. = Up to a maximum of the bolt hole circle diameter minus one bolt hole diameter unless gasket is to be full face. If gasket is to be full face, then the following must be specified: (a) Bolt hole circle diameter (b) Bolt hole diameter (c) Number of bolt holes (d) Desired gasket 0.0.
STANDARD
TOLERANCES
Up to 6" Diameter Gasket 6" to 60" 60" and Above
1-
+ 1132" - 0I.D. + 1116" - 0 + 3132" -
0
+ 0
The CMG, similar to the 360G, is manufactured with flexible graphite sheet, instead of tape, adhered to both gasket faces. This type of gasket niakes an excellent product for both standard flange gaskets and heat exchanger type gaskets where there is low bolt load or high availablegasket stresses. On flange width less than 1/2" please consult Lamons engineering department. Available in metal thicknesses of .015"to .032"and flexible graphite thickness in .015" to .030". Also availablewith anti-stick graphite.
Other methods of enhancing a seal include cementing non-asbestosor fiberglass cord to the corrugated faces or the use of a gasket compound. The temperature range for this type of gasket depends on the media to be sealed and the selection of the metal and/or facing materials. Corrugated gaskets can be fabricated in a wide variety of shapes with almost no size limitation.
- %2" __-"'D. + 0 - '/16" + 0 -
3/32"
19
LAMONS METAL CLAD AND SOLID METAL HEAT EXCHANGER GASKETS J
INFORMATION NEEDED TO FILL AN ORDER:
Ct
1. Outside diameter. 2. Inside Diameter 3. Shape per Standard Shapes Index 4. Lamons style per catalog, or type of construction 5. Thickness 6. Materials (metal or metal and filler) 7. Rib size 8. Distance from centerline of gasket to centerline of ribs 9. Radii
Ct
" --
Examples: Qty. holes
-cp
-St
v
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J
20
LAMONS
HEAT EXCHANGER
GASKETS
- STANDARD SHAPE INDEX
'-"
08CJOO§@8 8 0e90 @§~@j R
C-1
E-4
C-2
F-1
D-1
F-2
D-2
F-3
G-1
E-1
E-2
E-3
G-2
G-3
G-4
@8S~EB ~@8 G-5
G-6
G-7
G-8
G-9
H-1
H-2
H-3
'-"
§@@e@9~E9 e @@C§j@@~~ H-4
H-5
H-12
H-6
1-1
H-7
1-2
1-3
H-8
H-9
H-10
H-11
1-4
1-5
1-6
1-7
J-1
J-2
J-3
J-4
@@@~-@@§EB 1-8
'"""'"
1-9
1-10
1-11
@~E9C9~@~@ ~
~
H
~
~
~
~
~ 21
SPIRAL-WOUND
GASKETS SIZING SPIRAL WOUND GASKETS Spiral-wound gaskets must be sized to ensure the spiral-wound component is seated between flat surfaces. If it protrudes beyond a raised face or into a flange bore, mechanical damage and leakage may occur.
~
~
,.,~
i
Small Tongue and Groove Joint
Large Tongue an,d Groove
J~jnt
"
Spiral-wound gaskets have become extremely popular due to the wide variety of available styles and sizes. Spiralwound gaskets can be fabricated of any metal which is available in thin strip and which can be welded; therefore, they can be used against virtually any corrosive m~dium dependent upon the choice of the metal and filler. They can be used over the complete temperature range from cryogenic to approximately 2000°F. This type gasket can be used in all pressures from vacuum to the standard 2500 psi flange ratings. They are more resilient than any other type of metallic gasket with the exception of pressure sealing metal gaskets and, as a consequence, can compensate for flange movement that may occur due to temperature gradients, variations of pressure and vibration. Spiral-wound gaskets can also be manufactured with variable densities, i.e. relatively low density gaskets for vacuum service up to extremely high density gaskets having a seating stress of approximately 30,000 psi. The softer gaskets would require a seating stress in the range of 5,000 psi.
VARIABLE DENSITY Spiral-wound gaskets are manufactured by alternately winding strips of metal and soft fillers on the outer edge of winding mandrels that determine the inside dimensions of the wound component. In the winding process, the alternating plies are maintained under pressure. Varying the pressure during the winding operation and/or the thickness of the soft filler, the density of the gasket can be controlled over a wide range. As a general rule, low winding pressure and thick soft fillers are used for low pressure applications. Thin fillers and high pressure loads are used for high pressure applications. This of course would account for the higher bolt loads that have to be applied to the gasket in high pressure applications. In addition to all these advantages of the spiral-wound gasket, they are a relatively low cost. When special sizes are required, tooling costs are very nominal. 22
v
~~ ~
Large Male and 'female Joint
un:n? Raised Face Flange
,I GASKET CONFINED ON I.D. AND O.D. Gasket I.D. = Groove I.D. +1/16" Gasket a.D. = Groove a.D.-1/16"
GASKET CONFINED ON O.D. ONLY Gasket I.D. = Bore + Minimum 1/4" GasketaD. = Recess a.D. - 1/16" GASKET UNCONFINED I.D. AND O.D. Gasket I.D. = Seating Surface 1.0. + Minimum 1/4"
Gasketa.D. = SeatingSurfacea.D. Centering Guide aD. eter of Bolt
STANDARD
TOLERANCES
Gasket Diameter
-
Minimum1/4"
= Bolt Circle Diameter
I
Diam-
-
(STYLE W) 1.0.
0.0.
+3/64
1" to 24"
+ '/32 -0
+0 -'/32 +0 -'/32
24" to 36"
+3/64 -0
+0 -'/16
36"
+ '/'6 -0
-'/'6
-0
Up to 1"
to 60"
60" and above
I
+3/32 -0
+0 +0 _3/32
Thickness + .015 -.000 on special Gaskets with: a. less than 1" I.D., greater than 26" I.D. b. teflon fillers c. 1" or larger flange width. Thickness + .010 -.000 for most other sizes and materials
v
"-'"
AVAILABLE SIZES AND THICKNESSES Lamons spiral-wound gaskets are available in thicknesses of ,0625", ,100", ,125", ,175", .250", and ,285", The followingchart indicates the size range that can normally be fabricated in the various thicknesses along withthe recommended compressed thickness of each and the maximum flange width, LIMITATIONS OF SIZE AND THICKNESS Maximum Recommended Gasket Maximum Flange Compressed Thickness I.D. * Width * Thickness ,0625" 9' 3jg" ,0501.055" .100" 12" Vz" ,075/.080" .125' 40" 3/4" .0901.100" ,175" 75" 1" .125/.135" ,250" 160" 1114" ,1801,200" .285" 160" 1114" ,2001.220" *These limitationsare intended as a general guide only.Materialsof construction and flange width of gasket can drastically affect the limitations listed.
FLANGE
SURFACE
FINISH
Use of spiral-wound gaskets gives the designer and the usera wider tolerancefor flangessurfacefinishesthan other metallic gaskets, While they can be used against most commercially availableflange surface finishes, experience has indicated that the appropriate flange surface finishes used with spiral-wound gaskets are as follows:
~
125 to 250 AARH Optimum 500 AARH Maximum
gasket properly in the flange joint, acts as an antiblowout device, provides radial support for the spiralwound component, and acts as a compression gauge to prevent the spiral-wound component from being crushed, Normally the outer guide rings are furnished in mild steel, but can be supplied in other metals when required by operating conditions, LAMONS' STYLE WRI
Style WRI is identical to style WR with the addition of an inner ring, The inner ring serves several functions, It provides radial support for the gasket on the 1.0, to help prevent the occurrence of buckling or imploding, Its 1.0, is normally sized slightly larger than the 1.0, of the flange bore, minimizing turbulence in process flow, After the gasket is compressed, the flanges would normally be in contact with the inner ring and hence erosion and corrosion of the flange surface between the 1.0, of the sealing component and the flange bore is minimized. The inner rings are normally supplied in the same material as the spiral-wound component. Refer to table below for dimensions of inner ring ID,'s for flanges up to 24-inch diameter and 2500 PSI, Standard
for Spiral-Wound Flange Size INPS)
0.56 0.81 1.06 1.50 1.75
0.56 0.81 1.06 1.50 1.75
3 4
2.19 2.62 3.19 4.19
219 2.62 3.19 4.19
4.04
2.19 2.62 3.10 4.04
5
5.19
5.19
5.05
6 8 10 12 14
6.19 8.50 10.56 12.50 13.75
6.19 8.50 10.56 12.50 13.75
6.10 8.10 10.05 12.10 13.50
ety of styles to suit the particular flange facing being utilized on the flanges, LAMONS' STYLE W
16
15.75
15.75
18 20 24
17.69 19.69 23.75
17.69 19.69 23.75
Style W is a spiral-woundsealing component only that is normally used on tongue and groove joints, male and female flange facings and groove to flat flange facings.
LAMONS' STYLE WR
2'1,
Diameters (Inches)
P,...",e Cia.. 0:56 0.81 1.06 1.50 1.75
2
Lamons spiral-wound gaskets are available in a vari-
Gaskets
300
% 1 1'1, 1%
SEAL STYLES
Inside
150
%
AVAILABLE SPIRAL
Inner-Ring
400 (1)
600
gOO (1, 2)
1500
12, 31
2500
11-31
0.56 0.81 1.06 1.31 1.63
0.56 0.81 1.06 1.31 1.63
3.10 4.04
2.06 2.50 3.10 3.85
2.06 2.50 3.10 3.85
505
5.05
4.90
4.90
6.10 8.10 10.05 12.10 13.50
6.10 7.75 9.69 11.50 12.63
5.80 7.75 9.69 11.50 12.63
5.80 7.75 9.69 11.50
15.35
15.35
14.75
14.50
17.25 19.25 23.25
17.25 19.25 23.25
16.75 19.00 23.25
16.75 18.75 22.75
Note: The inner-ring thickness shall be 0.112 - .131 inches. Forsizes NPS 1 1/4 through NPS 3, the Ins,de-d,ameter tolerance,s I 0,03 ,nch: for larger sozes the Inside-diameter tolerance IS I 0.06 inch See ASME 816.20 for minimum pipe wall fhicknesses that are suitable for use with standard inner rings. ASME 816.20 calls for the use of inner rings with PTFE filled spiral wound gaskets "There are no Class 400 flanges NPS 1/2 through NPS 3 (use Class 6001. Class 900 flanges NPS 1/2 through NPS 2 1/2 (use Class 1500), or Class 2500 flanges NPS 14 and larger 'The inner-ring inside diameters shown for NPS 1 1/4 through NPS 2 1/2 in Classes 1500 and 2500 w,1I produce inner-ring widths of 0.12 ,nch, a pract,cal m,mmum for production purposes 'Innerrings are required for Class 900, NPS 24 gaskets; Class 1500, NPS 12 through NPS 24 gaskets: and Class 2500. NPS 4 through NPS 12 gaskets.
LAMONS' STYLE WR-RJ
...........
Style WR gaskets consist of a spiral"wound sealing component with a solid metal outer guide ring, These gaskets are used on plain flat face flanges and on raised face flanges. The outer guide ring serves to center the
This style gasket is identical to a Style WR in construction features but is specially sized to be used as a replacement gasket for flanges machined to accept oval 23
or octagonal ring joint gaskets. The sealing component is located between the 1.0.ofthe groove machined in the flange and the flange bore. These are intended to be used as replacement parts and are considered a maintenance item. In new construction, where spiral-wound gaskets are intended to be used, raised face flanges should be utilized. Referto Lamon SpiraSealCatalog for dimensions of Style WR-RJ gaskets for flanges up to 24-inch d,ameter and 1500 psi.
GASKETS WITH WOUND GAUGE RINGS
These gaskets are available in round, obround, and oval shapes and are used for standard manhole cover plates. (Referto Lamons SpiraSealCatalog for standard available shapes and sizes.) When special gaskets are required, it is necessary to submit complete information, including a sketch or blueprint or a sample cover on which the gasket is to be used. NOTE: When spiral-wound hand hole and manhole gaskets with a straight side are required it is necessary that some curvature be given to the flat or straight side to prevent buckling of the gasket. This is due to the fact that spiral-wound gaskets are wrapped under tension and therefore tend to buckle inward when the gaskets are removed from the winding mandrel. As a rule of thumb, the ratio of the long 10 to the short 10 should not exceed 3 to 1.
'-.J
LAMONS' STYLE WP OR WRP When a guide ring is required that is too narrow for practical fabrication of solid metal guide rings, Lamons spiral-wound gaskets are available with a guide made entirely of spiral metal windings. These spiral metal windings serve the same basic purpose as the solid metal ring,that is as acompression limiting and acentering device. The spirally wound ring is normally supplied in the same metal as the metal inthe gasket. This type of wound guide ring is normally limited to a V4" radialwidth or less.
LAMONS' STYLE H
These gaskets are similar to Style Wand Style WR with the addition of pass partitions for use with shell and tube heat exchangers. Partitions are normally supplied with a double-jacketed construction of the same material as the spiral-wound component. The partition strips can be soft soldered, tack welded or silver soldered to the spiral-wound component. The double-jacketed partition strips are normally slightly thinner than the spiralwound component in order to minimize the bolt loading required to properly seat the gasket.
"
J
LAMONS' STYLE L
Style H gaskets are for use on boiler handhole and tubecap assemblies. They are available in round, square, rectangular, diamond, obround, oval and pear shapes. The Lamons Gasket Company has tooling available for manufacturing most of the standard handhole and tubecap sizes of the various boiler manufacturers. (Refer to our SpiraSealCatalog.) These are also available in special sizes and shapes. To order special gaskets, dimensional drawings or sample cover plates should be provided in order to assure proper fit.
LAMONS' STYLE MW AND MWC
24
The Lamons Style L gasket is available for raised face and flat face applications where it is not practical to supply an outer gauge ring. The spiral-wound components of Style L are identical to those of Style Wand in addition have a wire loop welded to the outer periphery of the gasket, sized so as to fit over diametrically opposite bolts, for proper centering of the spiral-wound component on the gasket seating surface. Whenever possible, it is recommended that a Style WR gasket be used in lieU of a Style L gasket because of the obvious advantages of the outer solid metal gauge ring. The Style L is considerably more difficult to produce than the Style WR and therefore more expensive.
J
STYLE,
WR-LC
""-'
The need for a low compressive load spiral wound gasket in 150# and 300# class ASME/ANSI B16.5 pipe flange applications resulted in the development of the "WR-LC" spiral wound. The design of our gasket allows it to be compressed with less bolt load to seat compared to the conventional type spirals. The soft filler materials commonly used are graphite and PTFE. When selecting PTFE for your filler material the use of an inner ring is recommended (style WRI-LC).
WRI HF GASKETS This gasket was developed for H.F.acid applications. It consists of a Monel and PTFE spiral wound gasket with a carbon steel centering ring and a PTFE inner ring. The carbon steel outer ring can be coated with special H.F. acid detecting paint if desired. The PTFE inner ring reduces corrosion to the flanges between the bore of the pipe and the I.D. of the spiral wound sealing element. Inner ring I.D.'sare the same as standard metal inner rings unless otherwise requested. Thickness of the PTFE inner ring is .150
::1:.005
normally.
STYLE, WR-AB Spiral wounds that inwardly buckle are a concern in the industry and Lamons has introduced a spiral wound that addresses this historical concern. The traditional method to reduce inward buckling is to order an inner ring and that is still the best practice today. Lamons has a new style spiral called "WR-AB" that does not require an inner ring. There are many additional advantageous design features to this product to reduce inward buckling.
'-'"
(Contact Lamon's Technical Department or may not be appropriate.)
regarding flange bore sizes for which this gasket may
STYLE, WRI-HTG For applications requiring a spiral wound when oxidation may occur, usually at higher temperatures, Lamons has developed the "WRI-HTG". This gasket combines the corrosion and oxidation resistance of mica with the excellent sealability of flexible graphite. The mica along with the metal winding serves as a barrier between oxidizing process conditions and the external air and the graphite. This gasket can be ordered for any ASME/ANSI B16.5 and ASME B16.47 series A or B flange or for special applications
WRI-LP Winding
'-"
Graphiteor PTFEFacing
A Spiralwound gasket with a conventional outer guide ring with a special inner ring design. This special inner ring design is our "Kammpro" profile style LP-1. The uniqueness of the "kammpro" design allows numerous choices on its construction. The "WRI-LP" allows the spiral winding to be PTFE-Coated constructed with the required metal and soft filler specified by the user. The Kammpro "Kammpro" inner ring metal can be ordered with or without PTFE coating and then faced with either .020" thick PTFE, graphite or other materials.
25
SECTION III - RECOMMENDED GASKET INSTALLATION PROCEDURES INSTALLATION AND MAINTENANCE TIPS FOR ALL GASKETS All too often we hear "the gasket leaks." However, that is not entirely true. Technically, it is the joint that leaks, and the gasket is only one of several components that make up the joint. Often times, the gasket is expected to compensate for deficiencies in flange connection design, improper gasket installation procedures, and any flange movement that may occur due to thermal and pressure changes, vibration, etc. In many cases, the gasket has the ability the overcome these occurrances, but only when careful attention has been given to all of the aspects of gasket selection, including installation procedures. Our experience in investigating leaky joints over the years has indicated that the most common cause of leaky joints is the use of improper gasket installation procedures.
6.
7.
8.
9. 10.
GASKET INSTALLATION PROCEDURES (AND BOLT TORQUING) 1. Inspect the gasket. It is important that the correct gasket has been chosen for the bolted flange connection. Verify that the material is as specified and visually inspect the gasket for any obvious defects or damage. 2. Inspect the gasket seating surfaces. Look for tool marks, cracks, scratches, or pitting by corrosion. Radial tool marks on a gasket seating surfaces are virtually impossible to seal regardless of the type of gasket used. Therefore, every attempt should be made to minimize these. 3. Use only new studs or bolts, nuts and washers. Make sure they are of good quality and appropriate for the application. 4. Lubricate all thread contact areas and nut facings. The importance of proper lubrication cannot be overstated! A proper lubricant will provide a low coefficient of friction for more consistent achieved bolt stress. An anti seize compound, when used as a bolt and nut lubricant, will facilitate subsequent disassembly. 5. Loosely install stud bolts. With Raised face and flat face installation, loosely install the stud bolts on the lower half of the flange. Insert the gasket between the flange facing to allow the bolts to center the gasket on the assembly. Install the remaining bolts and nuts and bring all to a hand-tight or snug condition. In a recessed or grooved installation, center the gasket midway into the recess or groove. (If the joint is vertical, it may be necessary to use a minimum amount of cup grease, gasket cement, or some other adhesive compatible with the process fluids, to keep the gasket in position 26
11.
12.
until the flanges are tightened.) Then, install all bolts and nuts to a hand-tight or snug condition. Identify the proper bolting sequence and number bolts accordingly. See charts for recommended bolting sequences. Each bolt should be numbered so that bolt torque sequences can be easily followed. Failure to follow proper bolt torque sequences can result in cocking flanges. Then, regardless of the amount of subsequent torquing, they cannot be brought back to parallel. This can contribute heavily to a leaky joint. Torque the Bolts. Bolts should be torqued in a proper bolting sequence, in a minimum of four stages as specified in Steps 8, 9, 10, and 11. Torque the bolts up to a maximum of 30% of the final torque,value required following the recommended bolt torque sequence. Repeat Step 8, increasing the torque to approximately 60% of the final torque required. Repeat Step g, increasing the torque to the final torque value. Retorque all studs. All studs should be retorqued using a rotational pattern of retorquing to the final value of torque until no further rotation of the nuts can be achieved. This may require several retorquings as torquing of one stud causes relaxation in adjacent studs. Continue torquing until equilibrium has been achieved. Some flange joints should be retightened just before being put in operation, to account for bolt and gasket relaxation. Success has also been reported with heat exchangers, with certain gasket types* and flange facings, when bolting is retightened during initial heat up, before loss of lubricant (or bolt seizing).
J
J
*For specific gasket types and application assistance contact Lamons Technical Department
J
BOLT TORQUE SEQUENCE
12-Bolts
8-Bolts '"'"
Sequencial Order 1-2 3-4 5-6 7-8
Sequential Order 1-2 3-4 5-6 7-8 9-10 11-12
Rotational Order 1 5 3 7 2 6 4 8
'-'
Rotational Order 1 5 9 3 7 11 2 6 10 4 8 12
16-Bolts 9
12
11
10
..........
Sequential Order 1-2 3-4 5-6 7-8 9-10 11-12 13-14 15-16
Rotational Order 1 2 9 10 5 6 13 14 3 4 11 12 7 8 15 16
27
13
20-Bolts
16
3
4
15
14
2 Rotational 1 13 5 17 9 3 15 7 19 11
Sequential Order 1-2 3-4 5-6 7-8 9-10 11-12 13-14 15-16 17-18 19-20
Order 2 14 6 18 10 4 16 8 20 12
9
24-Bolts
12
3
4
11
10
Sequential Order 1-2 3-4 5-6 7-8 9-10 11-12 13-14 15-16 17-18 19-20 21-22 23-24
2 Rotational 1 9 17 5 13 21 3 11 19 7 15 23
Order 2 10 18 6 14 22 4 12 20 8 16 24
TORQUE VALUES Probably the only true measurement of bolt stress is by bolt or stud elongation. In practice, however, this would be an extremely costly and impractical approach to determine the true measure of bolt stress. As a con28
sequence the trend in industry today is the use of torque wrenches, tensioning devices, hydraulic wrenches, or drilling the studs and inserting heaters to preheat the stud to a specific temperature that will ultimately create the proper tension on the bolt. The use of manpower to tighten the bolts, by sledgehammers, striking wrenches and pieces of pipe on the end of the wrench is becoming less and less a standard practice. It is time-consuming, strenuous and is a very dangerous practice. The newer techniques are much more reliable.
NOTE: Allowable bolt stresses. Section VIII of the ASME Pressure Vessel Code, Appendix S, specifically recognizes the problem of initial bolt stresses. For example, a flange designer will determine his required bolting for a 600 psi application at a given operating temperature specifically in accordance with allowable stresses for the bolt material at the operating temperature. These allowable stresses are based on the particular material and their strength at operating temperature. In addition, the same bolt material will have an allowable stress at ambient conditions as specified. As a consequence, in most cases the design of the flange is based upon the allowable bolt stress of the particular material at design temperature and at the design or operating pressure. However, in most cases, the hydrostatic test pressure that the flange joint must pass is one and a half times the design pressure. As a consequence, any joint that is designed in strict accordance with the ASME Pressure Vessel Code and is subjected to hydrostatic tests in excess of the design pressure, will require a higher initial stress on the stud to successfully pass the hydrostatic test. Appendix S of Section 8 of the ASME Pressure Vessel Code speaks in great length on this problem and, in essence, states, that in order to pass hydrostatic tests, bolts may be stressed to whatever level is required to satisfactorily pass the test. This introduces additional problems. In cases where low yield bolt material is being used, the stresses required in bolts sufficient to satisfactorily pass the test may exceed the yield point of the bolt material. Once this occurs, no additional stressing of the bolt will alleviate the problem of leakage. As a consequence it may be necessary to use high tensile bolts or studs in order to achieve a satisfactory test. When this is required, the following procedures should be followed. (See Page 32)
I
~
. Use high tensile bolts or studs for hydrostatic tests following the procedures outlined above for gasket installation. After a successful hydrostatic test has been achieved, relievethe bolts to approximately 50 percent of the prestress required.
. Replace the bolts or studs one at a time with the proper grade bolt for operating conditions. As each bolt is replaced, torque it to the value of the other bolts.
. After all the bolts have been replaced, retorque the bolts to 100% of the allowable stress for the particular grade material. (Once again it is imperative that a proper lubricant be used on the bolts when replacement is being made.)
~
TROUBLE SHOOTING LEAKING JOINTS
'-'
One of the best available tools to aid in determining the cause of leakage is a careful examination of the gasket in use when leakage occurred. --
-------------
~
-~
~
-_u
~---~------------
Possible Remedies
Observation ~
n_-
~
Gasket badly corroded
Select replacement ------
n__-
Select replacement
Gasket extruded excessively
material with improved corrosion resistance. _.n.-
_no.
material with better cold flow properties,
replacement material with better load carrying capacity
~
select
i.e., more
dense. ~--~
'-'
---
--
-- --------------------------------------------------
n_.
Gasket grossly crushed
Select replacement material with better load carrying capacity, provide means to prevent crushing the gasket by use of a stop ring or re-design of flanges.
Gasket mechanically damaged due to overhang of raised face or flange bore.
Review gasket dimensions to insure gaskets are proper size. Make certain gaskets are properly centered in joint.
No apparent gasket compression achieved.
Select softer gasket material. Select thicker gasket material. Reduce gasket area to allow higher unit seating load.
Gasket substantially thinner on 0.0. than 1.0.
Indicative of excessive "flange rotation" or bending. Alter gasket dimensions to move gasket reaction closer to bolts to minimize bending movement. Provide stiffness to flange by means of back-up rings. Select softer gasket material to lower required seating stresses. Reduce gasket area to lower seating stresses.
Gasket unevenly compressed around circumference
Improper bolting up procedures followed. Make certain proper sequential bolt up procedures are followed.
-----------------
Gasket thickness varies periodically around circumference.
---
Indicative of "flange bridging" between bolts or warped flanges. Provide reinforcing rings for flanges to better distribute bolt load. Select gasket material with lower seating stress. Provide additional bolts if possible to obtain better load distribution. If flanges are warped, re-machine or use softer gasket material.
~---
..........
29
MANWAY PROBLEMS?
If installationand service problems are experienced with spiral wound gaskets in manways, Lamons has the answer In a typical oval or obround manway cover assembly, the cover sets inside of the boiler and internal pressure is relied upon to create the sealing force. Normally, these assemblies have a couple of bolts to secure the gasket during installation and provide some degree of initial seating load. Our experience indicates that, in this type of manways, there is often a large amount of clearance between the manway cover and the opening in the boiler.
"-"
A spiral wound gasket must be installed in such a manner that the winding is compressed across its entire face without interruption. If a spiral wound gasket falls into the clearances between a manway cover and boiler opening, a "pinching" effect may occur, causing mechanical damage to the gasket. It is possible to "bridge" the clearances in many boiler applications utilizing an integral solid metal ring along the inside circumference of the spiral windings, Lamons style MWI. Essentially, the inner ring helps to position the gasket on the manway cover. The thickness of the solid metal ring allows for adequate compression and helps to avoid crushing of the gasket. A Lamons technical representative could help with sizing of the inner ring and the sf3in~1WiHaing. The following page is an information sheet that would help us to assist you.
LAMONS STYLE MWI
,
Style MWI manway gaskets consist of a winding with a solid metal inner ring to position the winding and help avoid mechanical damage.
NOTES:
~
30
LAMONS GASKET COMPANY ,...,
Application
Information
Sheet For Oval or Obround
Manways
Boiler Manway Cover
~
1
i BoilerOpening Dim. (A)
t
ID of Gasket Surface on Cover Dim. (B)
t t
OD of Gasket Surface on goyer Dim. (C)
OD of Gasket Surface on Boiler Dim. (D)
'-" 1
r Boiler
Please provide the following information: Length (Long Side) Dim. A
Width (Short Side)
Shape (check one): Oval
c=::J
Obround
c=::J
Other
c=::J
(Drawing Required)
Dim. B Pressure
'-'
Dim. C
Temperature
Dim. D
Service (Typically Steam) Lamons Gasket Co. PO. Box 947 Houston, TX 77001 Fax (713) 547-9502 31
OTHER PROBLEM JOINT MUST COMPENSATE FOR WIDE TEMPERATURE VARIATIONS: Solution: Consider use of sleeve around bolts to increaseeffectivebolt length:
AREAS
Or consider use of conical spring washers in place of sleeve to eliminate torque losses over wide temperature ranges. BOLT
BOLT
.
;
WASHER SLEEVE
GASKET FLANGE FLANGE
-
GASKET WASHER FLANGE
-
NUT WASHER NUT
FLANGES BADLY COCKED OR SEPARATED TOO FAR: Solution: Do not try to correct problem with flange bolts - can overstress. Do use spacers to correct problem with gasket on each side. SPACER
n\ I
GASKET
Flanges
too far apart
GASKET
,
FLANGES OUT OF PARALLEL:
~ '-=f~:
'-'
Total allowable out of parallel: ~1 + ~2 = 0.015" . TAPERED SPACER
Flanges
Note - Deviation on right is less critical than deviation on left since bolt tightening will tend to bring flanges parallel due to flange bending.
cocked GASKET.
J
lASKET
WAVY SURFACE
Flanges badly mis-aligned
GASKET
~
! ~
j 32
1
Note:
FINISH
~~
1. If using jacketed or spiral wound gaskets - deviation should not exceed 0.015". 2. If using solid metal gaskets - deviation should not exceed 0.005". 3. If using rubber, more leeway is possible - perhaps total of 0.030".
v
SECTION IV
The primary purpose of the rules for bolted flange connections in Parts A and B of Appendix II is to insure safety,but there are certain practical matters to be taken into consideration in order to obtain a serviceable design. One of the most important of these is the prof
"-"
APPENDIX
APPENDIX S ASME SECTION VIII DIVISION I PRESSURE VESSELS DESIGN CONSIDERATIONS FOR BOLTED FLANGE CONNECTIONS
"-"
.........
-
portioningof the bolting,Le., determiningthe number
and size of the bolts. In the great majority of designs the practice that has been used in the past should be adequate, viz., to follow the design rules in Appendix II and tighten the bolts sufficiently to withstand the test pressure without leakage. The considerations presented in the following discussion will be important only when some unusual feature exists, such as a very large diameter, a high design pressure, a high temperature, severe temperature gradients, an unusual gasket arrangement, and so on. The maximum allowable stress values for bolting given in the various tables of Subsection C are design values to be used in determining the minimum amount of bolting required under the rules. However, a distinction must be kept carefully in mind between the design value and the bolt stress that might actually exist or that might be needed for conditions other than the design pressure. The initial tightening of the bolts is a prestressing operation, and the amount of bolt stress developed must be within proper limits, to insure, on the one hand, that it is adequate to provide against all conditions that tend to produce a leaking joint, and on the other hand, that is not so excessive that yielding of the bolts and/or flanges can produce relaxation that also can result in leakage. The first important consideration is the need for the joint to be tight in the hydrostatic test. An initial bolt stress of some magnitude greater than the design value therefore must be provided. If it is not, further bolt strain develops during the test, which tends to part the joint and thereby to decompress the gasket enough to allow leakage. The test pressureis usually 11/2 times the design pressure, and on this basis it may be thought that 50 percent extra bolt stress above the design value will be sufficient. However, this is an oversimplification, because, on the one hand, the safety factor against leakage under test conditions in general need not be as great as under operating conditions. On the other hand, if a stress-strain analysis of the joint is made, it may indicatethat an initial bolt stress still higher than 11/2 times the design value is needed. Such an analysis is one that considers the changes in bolt elongation, flange deflection, and gasket load that take place with the application of internal pressure, starting from the prestressed condition. In any event, it is evident that an initial bolt stress higher than the design value may and, in some cases, must be developed in the tightening operation, and it is the intent of this Division of Section VIII that such a practice is permissible, provided it includes necessary and appropriate provision to insure against excessive flange distortion and gross crushing of the gasket.
It is possible for the bolt stress to decrease after initial tightening, because of slow creep or relaxation of the gasket, particularly in the case of the "softer" gasket materials. This may be the cause of leakage in the hydrostatic test, in which case it may suffice merely to retighten the bolts. A decrease in bolt stress can also occur in service at elevated temperatures, as a result of creep in the bolt and/or flange or gasket material, with consequent relaxation. When this results in leakage under service conditions, it is common practice to retighten the bolts, and sometimes a single such operation, or perhaps several repeated at long intervals, is sufficient to correct the condition. To avoid chronic difficulties of this nature, however, it is advisable when designing a joint for high-temperature service to give attention to the relaxation properties of the materials -involved,especially for temperatures where creep isthe controlling factor in design. This prestress should not be confused with initial bolt stress, S1'used in the design of Part B flanges. In the other direction, excessive initial bolt stress can present a problem in the form of yielding in the bolting itself, and may occur in the tightening operation to the extent of damage or even breakage. This is especially likely with bolts of small diameter and with bolt materials having a relatively low yield strength. The yield strength of mild carbon steel, annealed austenitic stainless steel, and certain of the nonferrous bolting materials can easily be exceeded with ordinary wrench effort in the smaller bolt sizes. Even if no damage is evident, any additional load generated when internal pressure is applied can produce further yielding with possible leakage. Such yielding can also occur when there is very little margin between initial bolt stress and yield strength. An increase in bolt stress, above any that may be due to internal pressure, might occur in service during startup or other transient conditions, or perhaps even under normal operation. This can happen when there is an appreciable differential in temperature between the flanges and the bolts, or when the bolt material has a different coefficient of thermal expansion than the flange material. Any increase in bolt load due to this thermal effect, superposed on the load already existing, can cause yielding of the bolt material, whereas any pronounced decrease due to such effects can result in such a loss of bolt load as to be a direct cause of leakage. In either case, retightening of the bolts may be necessary, but it must not be forgotten that the effects of repeated retightening can be cumulative and may ultimately make the joint unserviceable. In addition to the difficulties created by yielding of the bolts as described above, the possibility of similar difficulties arising from yielding of the flange or gasket material, under like circumstances or from other causes, should also be considered. Excessive bolt stress, whatever the reason, may cause the flange to yield, even though the bolts may not yield. Any resulting excessive deflection of the flange, accompanied by permanent set, can produce a leaking 33
joint when other effects are superposed. It can also damage the flange by making it more difficult to effect a tight joint thereafter. For example, irregular permanent distortion of the flange due to uneven bolt load around the circumference of the joint can warp the flange face and its gasket contact surface out of a true plane. The gasket, too, can be overloaded, even without excessive boltstress. The full initial bolt load is imposed entirely on the gasket, unless the gasket has a stop ring or the flange face detail is arranged to provide the equivalent. Without such means of controlling the compression of the gasket, consideration must be given to the selection of gasket type, size and material that will prevent gross crushing of the gasket. From the foregoing, it is apparent that the bolt stress can vary over a considerable range above the design stress value. The design stress values for bolting in Subsection C have been set at a conservative value to provide a factor against yieJding.At elevated temperatures, the design stress values are governed by the creep rate and stress-rupture strength. Any higher bolt stress existing before creep occurs in operation will have already served its purpose of seating the gasket and holding the hydrostatic test pressure, all at atmospheric temperature, and is not needed at the design pressure and temperature. Theoretically,the margin against flange yielding is not as great. The design values for flange materials may be as high as five-eighths or two-thirds of the yield strength. However, the highest stress in a flange is usually the bending stress in the hub or shell, and is more or less localized. It is too conservative to assume that local yielding isfollowed immediately by overall yielding of the entire flange. Even if a "plastic hinge" should develop, the ring portion of the flange takes up the portion of the load the hub and shell refuse to carry. Yielding is far
more significant if it occurs first in the ring, but the limitation in the rules on the combined hub and ring stresses provides a safeguard. In this connection, it should be noted that a dual set of stresses is given for some of the materials in Table UHA-23, and that the lower values should be used in order to avoid yielding in the flanges. Another very important item in bolting design is the question whether the necessary bolt stress is actually realized, and what special means of tightening, if any, must be employed. Most joints are tightened manually by ordinary wrenching, and it is advantageous to have designs that require no more than this. Some pitfalls must be avoided, however. The probable bolt stress developed manually,when using standard wrenches, is: S = 45,000 y'd where S is the bolt stress and d is the nominal diameter of the bolt. It can be seen that smaller bolts will have excessive stress unless judgment is exercised in pulling up on them. On the other hand, it will be impossible to develop the desired stress in very large bolts by ordinary hand wrenching. Impact wrenches may prove serviceable, but if not, resort may be had to such methods as preheating the bolt, or using hydraulically powered bolt tensioners. With some of these methods, control of the bolt stress is possible by means inherent in the procedure, especially if effective thread lubricants are employed, but in all cases the bolt stress can be regulated within reasonable tolerances by measuring the bolt elongation with suitable extensometer equipment. Ordinarily, simple wrenching without Verification of the actual bolt stress meets all practical needs, and measured control of the stress is employed only when there is some special or important reason for doing so.
J
J
Reprinted with permission from ASME.Reprinted from ASME Unfired Pressure Vessel Code, Section VIIi, Div.
J
34
'-"
'-"
"-'
CHEMICAL A - Good Resistance B - Moderate Resistance U - Unsatisfactory Media Acetic Acid Room Temp. Acetic Anhydride Room Temp. Acetone Aluminum Chloride Room Temp. Aluminum Fluoride Room Temp. Aluminum Sulphate Ammonia (Anhydrous) Ammonium Chloride Ammonium Hydroxide Ammonium Nitrate Ammonium Phosphate Ammonium Sulphate Amyl Acetate Aniline Barium Chloride Beer Benzene Benzol Borax Boric Acid Bromine Butyl Alcohol Calcium Carbonate Calcium Chloride Calcium Hydroxide Calcium Hypochlorite Carbolic Acid Carbon Tetrachloride Chlorine-Dry Chlorine-Wet Chromic Acid Citric Acid Copper Chloride Copper Sulphate Creosote (Coal Tar) Crude Oil Ether Ethyl Acetate Ethyl Chloride Ferric Chloride Ferric Sulphate Formaldehyde Formic Acid Fuel Oil Fuel Oil (Acid) Furfural Gasoline Glue Glycerin Hydrobromic Acid Hydrochloric Acid Room Temp. 150°F Hydrocyanic Acid Hydrofluoric Acid Hydrofluosilicic Acid Hvdroqen Peroxide Hydrogen Sulphide Kerosene Lactic Acid Linseed Oil
RESISTANCE
-
CHART
GASKET
METALS
Alurni- Alloy Hastel- Inconel Monel Nickel 304 316 410 nurn 20 Copper loy 600 400 200 S.S. S.S. S.S. Steel A
A
A
A
B
B
B
A
A
A
U
A A
A A
A A
A A
B A
B A
A A
A A
A A
A A
B A
U
A
B
A
-
B
B
U
U
U
U
B B A U B A A U A B B A A A A A A A A B B U A B A U B A U U B A A A B U B B U A B A A A A U U U A U A A A B A
A A A A A A A A A A A A A A A A A A A A U A A A U A A A A A A A A U A A A A A A A A A U U U A U A A A A A A
B B U U U U t:; B A A B A A A A A A A A A A U A B A U U A U B A B A A A U B A A A B A A A A U U U C U U C A A A B
A A A A A A A A A A A A A A A A A A A A A A A A A U A A A A A A A A A A A A A A A A A A A A A A A A A A A A A
8 A A A B B B A B A A A B A B A A A A B U B A A B B B U B B B A U U A B B U B A A A U U U A B B B A B A
B B B B U U B B A B. A A A A B A A A B B U B A A B U B U B B B B A B U U A B B B A A A A U U U B A B B A U A
B B B B U U B B A B B A B B B A A A B B B B A A B U B U B B B A B U U A B A U B A A A U U U A B B B A U A
U A A U A A A U A A B A A A A A U A A B B B A A U U A A U A A A A A A U A A B A U A A A A U U U A U U A A A B A
U A A B A A A A A A A A A A A A U A A A B A A A U U A A B A A A A A A U A A A A B A A A A U U U A U U A A A B A
U B A B A A A A A A A A A A A U A A U A B U A U U B A B A A A A U A A U A A A U U U U U A A A A A
B U B B A A U A B A B A A A A U U A A A A U U U A U U B U A A A A A U U B U A B A A A A U U U B U U U U A U A
35
CHEMICAL
RESISTANCE
CHART
-
GASKET
METALS
(CONT.)
A - Good Resistance B - Moderate Resistance U - Unsatisfactory Media Lye (Caustic) Manganese Carbonate Manganese Chloride Mangnesium Carbonate MaQnesiumChloride Magnesium Hydroxide Magnesium Nitrate Magnesium Sulphate Methylene Chloride Mercuric Chloride Mercury Muriatic Acid Nitric Acid-Diluted Nitric Acid-Concentrated Nitrous Acid Nitrous Oxide Oleic Acid Oxalic Acid Petroleum Oils-Crude Phosphoric Acid Picric Acid Potassium Bromide Potassium Carbonate Potassium Chloride Potassium Cvanide Potassium Hydroxide Potassium Sulphate Sea Water Sewage Silver Nitrate Soaps Sodium Bicarbonate Sodium Bisulphate Sodium Bromide Sodium Carbonate Sodium Chloride Sodium Hydroxide Sodium Hyperchlorite Sodium Nitrate Sodium Peroxide Sodium Phosphate Sodium Silicate Sodium Sulphate Sodium Sulphide Soy Bean Oil Steam Stearic Acid Stannic Chloride Sulphur Chloride Sulphur Dioxide-Dry Sulphuric Acid-<10%-Cold Sulphuric Acid-<10%-Hot Sulphuric Acid10-50%-Cold
Sulphuric Acid10-50%-Hot Sulphuric Acid-Fuming Sulphurous Acid Sulphur-Molten Tannic Acid Tartaric Acid Vinegar Zinc Chloride Zinc Sulphate
36
Alurni- Alloy Hastel- Inconel Monel Nickel 304 nurn 20 Copper loy 600 400 200 5.5. U A B A A A A A B B B A A A A A U B B B B B B A A A A A A A A A A A B A B A A A U A A A A A B B B A A A A A A A A B B B A U U U A U U U U U U U A U U U U U A U A A B B A U U U A U U U U U A A U U U U A A A U A U U U A B A B B A A A A A U A U A A A A A B B A B A A A B B .B A A A U A A A A A A A B A B B B U A A C A U U U A B B B A A A B A B A B A A A B A B A B A B B B A U A U A B B B A U A U A B A A B B B A A A B A B A B A B B B A B B A U A U B B A U U B A B A A A A A B A A A A A A A B A B A B B B A B A A A B B B A B B B B A A A A A A B A A A A A A U A B A A A A U B U A U U U B A A A A A B B A A A B B B B A A A A A A B B B A B A A A B A A A A A B B B A U A U A B B B A A A A B A A A B A A A A A A A A B B B A U A U A B B B A U A A A B B U A A A A A A A A B A B A U B B U U B U A U B U U
'-'"
316 5.5.
410 5.5.
Steel
A A A A A A A A U U A U A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A U A B U
B A A U A A U U A U A A A B A B A A A A U A A A A A U A A A B A A U U U U
A B A B A B U A U U U B B U A U A B B A A B A B B U A B U B A A A U A B B, A A A A B B A U U
U
A
U
A
U
B
U
U
U
-
U
U A B A B B B U B
U A A A A A A A A
U U U U A A B B A
A A A A A A A B A
U U U A B B A B B
U U U U B B A B B
U U U U B B A B B
U A U A A A A U A
U A B A A A A U A
U U A A U A U A
U B A A U U B B B
'--'
'--'
METALS SUGGESTED MAXIMUM SERVICE TEMPERATURES TYPE
IN AIR
CONTINUOUS
'-'
SERVICE
°C 538 760 1095 1150 760 815 925 705 815 649 815 427 260 260 1095 1095 871 815 760 260 1649 1095
Carbon 8teel 304 8.8. 309 8.8. 310 8.8. 316 8.8. 321 8.8. 347 8.8. 4108.8. 4308.8. 501 8.8. Alloy 20 Aluminum Brass Copper Hastelloy B & C@ Inconel 600@ Incolloy 800@ Monel@ Nickel Phosphor Bronze Tantalum Titanium
OF 1000 1400 2000 2100 1400 1500 1700 1300 1500 1200 1500 800 500 500 2000 2000 1f~00 1500 1400 500 3000 2000
Note: Maximum temperature ratings are based upon hot air constant temperatures. The presence of contaminating fluids and cyclic conditions may drastically affect the maximum temperature range.
"-'"
CHEMICAL RESISTANCE VEGETABLE FIBER SHEET Vegetable
CHART
GLUE- GLYCERIN BINDER
fiber sheet is a tough, pliable and compressible
protein bonded
sheet that is suitable
for the or
services listed below to a maximum temperature limit of 2500 F. For unusual concentrations,pressures temperatures, further investigation is indicated.
'-'
Suitable for use with: Acetone Alcohol Animal Fats & Oils Benzene (Benzol) Benzine (Gasoline) Bunker Oil Butane Butyl Acetate Carbon Dioxide Carbon Tetrachloride Cresol Dibutyl Phthalate DOP (Dioctyl Phthalate) Dry Cleaning Fluid Ether Ethyl Acetate Ethylene Glycol Formaldehyde Freon
Fuel Oil Gas Illuminating Gasoline Greases Hydrogen Hydrogen Sulphide Inerteen 70-30 Inks Kerosene Lacquers and Thinners Lubricating Oil Methyl Chloride (Refrigerant) Methyl Ethyl Ketone (MEK) Methyl Isobutyl Detone (MIBK) Naphtha, Petroleum Naphtha, Coal Tar Paints Petroleum Prestone (Antifreeze)
Not suitable for use with: Acids (Inorganic) Alkalies Hydrochloric Acid Nitric Acid (Dilute)
Nitro Benzine Oxygen Silicate of Soda Sulphuric Acid (Dilute)
Propylene Glycol Pyranol A13B3B Skydrol 500B Skydrol 7000 Abs. Soap Sperry Oil Sulphur Dioxide Super VM&P Naphtha Toluol Transformer Oil Trichloroethylene Tricresyl Phosphate Triethylene Glycol (Neutral Grade) Turpentine Varnish Vegetable Oil Water Wood Alcohol Xylol
37
SOFT SHEET GASKET SIZES PER ASME 816.21 GASKETDIMENSIONS FOR ASME/ANSI 816.5 CLASS 150 PIPE FLANGES AND FLANGED FullFaceGasket Nominal Flat Gasket Pipe Ring Size 10 00
FullFaceGasket
Nominal Flat No.of Hole BoltCircle Pipe Gasket Ring 10 Holes Diameter Diameter Size 00
00
J
FITTINGS
No.of Hole BoltCircle Holes Diameter Diameter
00
1/2 3/4 1 1 1/4
0.84 1.06 1.31 1.66
1.88 2.25 2.62 3,00
3.50 3.88 4.25 4.63
4 4 4 4
0.62 0,62 0.62 0.62
2.38 2.75 3.12 3.50
8 10 12 14
8.62 10.75 12.75 14.00
11.00 13.38 16,13 17.75
13.50 16.00 19.00 21.00
8 12 12 12
0.88 1.00 1.00 1.12
11.75 14.25 17.00 18.75
1 1/2 2 2 1/2 3
1.91 2.38 2.88 3.50
3.38 4.12 4,88 5.38
5.00 6.00 7.00 7.50
4 4 4 4
0.62 0.75 0.75 0.75
3.88 4.75 5,50 6.00
16 18 20 24
16.00 18.00 20.00 24.00
20.25 21.62 23,88 28.25
23.50 25.00 27.50 32.00
16 16 20 20
1.12 1.25 1.25 1.38
21.25 22.75 25,00 29.50
3 1/2 4 5 6
4.00 4.50 5,56 6.62
6.38 8.50 6.88 9.00 7.75 10.00 8.75 11.00
8 8 8 8
0.75 0.75 0.88 0.88
7.00 7.50 8,50 9.50
FLAT RING GASKET DIMENSIONS FOR ASME/ANSI 816.5 PIPE FLANGES AND FLANGED FITTINGS, CLASSES 300, 400, 600, AND 900
-..../
Gasket 00 NominalPipe Size
Gasket 10
Class 300
Class 400
Class 600
Class 900
1/2 3/4 1 1 1/4
0.84 1.06 1.31 1.66
2.12 2.62 2.88 3.25
2.12 2.62 2.88 3.25
2.12 2.62 2.88 3.25
2.50 2.75 3.12 3.50
1 1/2 2 21/2 3
1.91 2.38 2.88 3.50
3.75 4.38 5.12 5.88
3.75 4.38 5.12 5.88
3.75 4.38 5.12 5.88
3.88 5.62 6.50 6.62
31/2 4 5 6
4.00 4.50 5.56 6.62
6.50 7.12 8.50 9.88
6.38 7.00 8.38 9.75
6.38 7.62 9.50 10.50
... 8.12 9.75 11.38
8 10 12 14
8.62 10.75 12.75 14.00
12.12 14.25
12.00
12.62
14.12
15.75
16.62
16.50
19.12
19.00
18.00 19.38
14.12 17.12 19.62 20.50
16 18
16.00 18.00
21.25 23.50
21.12 23.38
22.25 24.12
22.62 25.12
20 24
20.00 24.00
25.75 30.50
25.50 30.25
26.88 31.12
27.50 33.00
38
V
SOFT SHEET GASKET SIZES PER ASME 816.21 (CONT.) FLAT RING GASKET DIMENSIONS FOR ASME B16.47 SERIES A (OR MSS-SP-44) LARGE DIAMETER STEEL FLANGES, CLASSES 150, 300, 400, AND 600
'-'
00 Nominal Pipe
Size
10
Class 150
Class 300
Class 400
Class 600
22 (1) 26 28 30
22.00 26.00 28.00 30.00
26.00 30.50 32.75 34.75
27.75 32.88 35.38 37.50
27.63 32.75 35.12 37.25
28.88 34.12 36.00 38.25
32 34 36 38
32.00 34.00 36.00 38.00
37.00 39.00 41.25 43.75
39.62 41.62 44.00 41.50
39.50 41.50 44.00 42.26
40.25 42.25 44.50 43.50
40 42 44 46
40.00 42.00 44.00 46.00
45.75 48.00 50.25 52.25
43.88 45.88 48.00 50.12
44.38* 46.38 48.50 50.75
45.50 48.00 50.00 52.26
48 50 52 54
48.00 50.00 52.00 54.00
54.50 56.50 58.75 61.00
52.12 54.25 56.25 58.75
53.00 55.25 57.26 59.75
54.75 57.00 59.00 61.25
56 58 60
56.00 58.00 60.00
63.25 65.50 67.50
60.75 62.75 64.75
61.75 63.75 66.25
63.50 65.50 67.75
GENERAL NOTE: Dimensions are in inches. * Dimension as suggested by Lamons. "'""NOTE: (1) NPS 22 for reference only. Size not listed in ASME 816.47.
FLAT RING GASKET DIMENSIONS FOR ASME B16.47 SERIES B (OR API 605) LARGE DIAMETER STEEL FLANGES, CLASSES 75, 150, 300, 400 AND 600 00
..........
Nominal Pipe Size
Gasket 10
Class 75
Class 150
Class 300
Class 400
Class 600
26 28 30 32
26.00 28.00 30.00 32.00
27.88 29.88 31.88 33.88
28.56 30.56 32.56 34.69
30.38 32.50 34.88 37.00
29.38 31.50 33.75 35.88
30.12 32.25 34.62 36.75
34 36 38 40
34.00 36.00 38.00 40.00
35.88 38.31 40.31 42.31
36.81 38.88 41.12 43.12
39.12 41.25 43.25 45.25
37.88 40.25
39.25 41.25
42 44 46 48
42.00 44.00 46.00 48.00
44.31 46.50 48.50 50.50
45.12 47.12 49.44 51.44
47.25 49.25 51.88 53.88
50 52 54 56
50.00 52.00 54.00 56.00
52.50 54.62 56.62 58.88
53.44 55.44 57.62 59.62
55.88 57.88 60.25* 62.75
58 60
58.00 60.00
60.88 62.88
62.19 64.19
65.19 67.12
GENERALNOTE: Dimensions are in inches. * Dimension as suggested by Lamons. 39
I
GRAFOIL@
CHEMICAL
SERVICE
RECOMMENDATION
Chemical Reagent ACIDS
Acetic acid Acetic anhydride Arsenic Acid Boric acid Carbonic Acid Chromium trioxide, aq. soln. Citric acid Formic acid Hydrobromic acid Hydrochloric acid Hydrofluosilicic acid Hydrogen chloride Hydrogen sulfide-water Lactic acid Monochloracetic acid Nitric acid Nitric acid Nitric acid Oleic acid Oxalic acid Phosphoric acid Stearic acid Sulfur dioxide Sulfuric acid Sulfuric acid Sulfuric acid Sulfuric acid Sulfuric acid Sulfurous acid Tartaric acid
ALKALIES
Ammonium hydroxide Monoethanolamine Sodium hydroxide
SALTSOLUTIONS
Alum Aluminum chloride Ammonium bifluoride Ammonium bisulfate Ammonium sulfate Ammonium thiocyanate Arsenic trichloride Calcium chlorate Calcium hypochlorite Copper sulfate Cupric chloride Ferric chloride Ferrous chloride Ferrous sulfate Manganous sulfate Nickel chloride Nickel sulfate Phosphorous trichloride Sodium chloride Sodium chlorite Sodium hypochlorite Stannic chloride Sulfur monochloride Zinc ammonium chloride Zinc chloride Zinc sulfate
40
CHART
Concentration Per Cent
Fluid Temp. up to of
All All All All All 0 - 10 All All All All 0 - 20 All All All All 0 - 10 10 - 20 Over 20 All All 0 - 85 All All 0 - 70 71 - 85 86 - 90 91 - 95 Over 95 All All
All All All All All 200 All All All All All All All All All 185 140 100 All All All All All All 338 300 160 Not Rec. All All
All All All
All All All
All All All All All 0 - 63 All 0 - 10 All All All All All All All All All All All 0-4 0 - 25 All All All All All
All All All All All All All 140 90 All All All All All All All All All All Room Room All All All All All
-....J
"-'
-...J
GRAFOIL@ CHEMICAL
SERVICE
RECOMMENDATION '-" HALOGENS,AIR, WATER
Chemical Reagent Air Bromine Bromine water Chlorine-dry Chlorine dioxide Chlorine water Fluorine Iodine Steam Water
HEAT TRANSFER FLUIDS
"Dowtherm" (all types) Petroleum-oil based "Therminol" (all types) "Ucon:' (all types)
ORGANIC COMPOUNDS
Acetone Amyl alcohol Aniline Aniline hydrochloride , 'Au reomyci
,",
'-"
I
n"
Benzene Benzene hexachloride Benzyl sulfonic acid Butyl alcohol Butyl "Cellosolve" Carbon tetrachloride "Cellosolve" solvent Chloral hydrate "Chlorethylbenzene" Chloroform "Deoxidine" Dichloropropionic acid Diethanolamine Dioxane Ethyl alcohol Ethyl chloride Ethylene chlorohydrin Ethylene dibromide Ethylene dichloride Ethyl mercaptan-water Fatty acids Folic acid Refrigerants 11 and 12 Gasoline Glycerine Isopropyl acetate Isopropyl alcohol Isopropyl ether Kerosene Mannitol Methyl alcohol Methyl isobutyl ketone Monochlorbenzene Monovinyl acetate Octyl alcohol Paradichlorbenzene Paraldehyde Tetrachlorothane, sym. Trichlorethylene Xylene
CHART
(CONT.)
Concentration Per Cent All All All All All All All All All All
Fluid Temp. Up to OF 850 Room Room All 158 Room 300 Room 1200 All
All All All All
All All All All
All All All 0 - 60 All All All 60 All All All All All All All
All All All All All All All All All All All All All All All 140 338 All All All All All All All All All All All All All All All All All All All All All All All All All All All All
-
90 - 100 All All All All 0 -8 All All Saturated All All All All All All All All All All All All All All All All All All All All
41
. --
GRAFOIL@ CHEMICAL SERVICE RECOMMENDATION CHART MIXTURES
(CONT.)
Concentration Per Cent
Chemical Reagent
All Acidified starch ,solutions Amino acid plus hydrochloric and sulfuric acids Ammonium persulfate plus Over 20 sulfuric acid All Anodizing solutions All Butyl acrylate plus acrylic acid 30 Calcium chloride 10 plus calcium chlorate All Chlorinated ethyl alcohols All Chrome plating solutions Cresylic acid plus sulfuric acid Electropolishing solutions (sulfuric All plus phosphoric acids) Over 20 Hydrochloric acid All sat. with chlorine All Nickel plating solns. (chloride) All Nickel plating solns. (sulfate) 15 Nitric acid plus 5 hydrofluoric acid All "Parkerizing" solution All Rayon spin bath 25 Sodium hypochlorite plus sodium hydroxide 96 Sulfuric acid plus .03 nitric acid
TYPICAL TYPICAL MATERIAL PROPERTIES
TYPICAL PHYSICAL PROPERTIES
TYPICAL THERMAL PROPERTIES
42
--
GRAFOIL@
SHEET
Density Leachable Chloride Content-Maximum Industrial Grades Premium (Nuclear) Grades Carbon Content-Minimum Industrial Grades Premium (Nuclear) Grades Compressibility (ASTM F-36) Recovery(ASTMF-36) Creep Relaxation (ASTM F-38) Sealability (ASTM F-37) TensileStrength Along Length & Width Coefficient of Friction Against Steel @ 4 psi (.03 MPa) @ 8 psi (.07 MPa) @ 12 psi (.08 MPa)
Fluid Temp. Up to of All
J
All Room All All 140 All Room All 140 All All All 140 All All 200 Not Rec.
PROPERTIES
'-'
70 Ib/fP 100 ppm 50 ppm 95.0% 99.5% 40% 20% <5% <0.5 ml/hr 900 psi .018 .052 .157
Functional/TemperatureRange -400 to 5400oF Neutral or Reducing Atmosphere -400 to 850oF* Oxidizing Atmosphere Standard Grades -400 to 975°F* Oxidation Resistant Grades GT"'J and GT'M K Thermal Conductivity Along Length & Width 960BTU-in/ft2.H.oF Through Thickness 36BTU-in/ft2.H.of * The fluid temperature in an oxidizing atmosphere may considerably exceed the indicated temperature without oxidation of the GRAFOIL@providing that the bulk temperature of the GRAFOIL@gasket is below these temperatures or that the fluid being handled does not come into direct contact with the graphite. EXAMPLE: a metal spiralwound gasket with a GRAFOIL@filler material.
J
.
'-'
Diam.
Area .00076
Diam. 8
Cire. 25.13
Area 50.265
Diam. 17
Cire. 53.40
Area 226.98
.1963 .3926 .5890 .7854 .9817 1.178 1.374
.00306 .01227 .02761 .04908 .07669 .1104 .1503
V8 V4 3/8 V2 5/8 3/4 \18
25.52 25.91 26.31 26.70 27.09 27.47 27.88
51.848 53.456 55.088 56.745 58.426 60.132 61.862
V8 V4 3/8 '/2 5/8 3f4 \18
53.79 54.19 54.58 54.97 55.37 55.76 56.16
5/8 11/,6 3f4 13/,6 \la 15/'6
1.570 1.767 1.963 2.159 2.356 2.552 2.748 2.945
.1963 .2485 .3097 .3712 .4417 .5184 .6013 .6902
9 V8 V4 3/a V2 5/8 3/4 7/8
28.27 28.66 29.05 29.45 29.84 30.23 30.63 31.02
63.617 65.396 67.200 69.029 70.882 72.759 74.662 76.588
18 V8 V4 3/a V2 5/a 3/4 \la
1 Va V4 3/8 V2 5/8 3f4 \18
3.141 3.534 3.927 4.319 4.712 5.105 5.497 5.890
.7854 .9940 1.227 1.484 1.767 2.073 2.405 2.761
10 Va V4 3/8 V2 5/a 3/4 7/a
31.41 31.80 32.20 32.59 32.98 33.37 33.77 34.16
78.539 80.515 82.516 84.540 86.590 88.664 90.762 92.885
2 Va V4 3/a V2
6.283 6.675 7.068 7.461 7.854 8.246 8.639 9.032
3.141 3.546 3.976 4.430 4.908 5.411 5.939 6.491
11 V8 V4 3/8 V2 5/8 3/4 \la
34.55 34.95 35.34 35.73 36.12 36.52 36.91 37.30
\18
9.424 9.817 10.21 10.60 10.99 11.38 11.78 12.17
7.068 7.669 8.295 8.946 9.621 10.320 11 .044 11.793
12 V8 V4 3/8 V2 0/8 3f4 7/8
4 V8 V4 3/S V2 5/a 3f4 7/a
12.65 12.95 13.35 13.74 14.13 14.52 14.92 15.31
12.566 13.364 14.186 15.033 15.904 16.800 17.720 18.665
5 V8 V4 3fa V2 5/8 \la
15.70 16.10 16.49 16.88 17.27 17.:.7 18.06 18.45
6 V8 V4 3fa V2 5/8 3/4 7/S 7 Va V4 3/a V2 5/8 3/4 \Is
1/16
V8 3/,6 V4 5/,6 3/8 7/,6 V2
5/8
3f4 \18 3 V8 V4 3/8 V2' 5/a 3f4
3/4
'-'
AND AREAS OF CIRCLES
Cire. .0981
1132
9/16
'-'
CIRCUMFERENCES
Diam. 26
Cire. 81.68
Area 530.93
Diam. 35
Cire. 109.9
Area 962.11
230.33 233.70 237.10 240.52 243.97 247.45 250.94
Va V4 3/8 V2 5/8 3/4 7/8
82.07 82.46 82.85 83.25 83.64 84.03 84.43
536.04 541.18 546.35 551.54 556.76 562.00 567.26
V8 V4 3/8 V2 5/8 3/4 7/8
110.3 110.7 111.1 111.5 111.9 112.3 112.7
968.99 975.90 982.84 989.80 996.78 1003.7 1010.8
56.54 56.94 57.33 57.72 58.11 58.51 58.90 59.29
254.46 258.01 261.58 265.18 268.80 272.44 276.1-1 279.81
27 V8 V4 3/a V2 5/8 3/4 \/a
84.82 85.21 85.60 86.00 86.39 86.78 87.17 87.57
572.55 577.87 583.20 588.57 593.95 599.37 604.80 610.26
36 V8 V4 3/a V2 5/8 3f4 \18
113.0 113.4 113.8 114.2 114.6 115.0 115.4 115.8
1017.8 1024.9 1032.0 1039.1 1049.3 1053.5 1060.7 1067.9
19 V8 V4 3/8 V2 5/8 3/4 \/8
59.69 60.08 60.47 60.86 61.26 61.65 62.04 62.43
283.52 287.27 291.03 294.83 298.64 302.48 306.35 310.24
28 V8 V4 3/8 V2 5/8 3f4 \18
87.96 88.35 88.75 89.14 89.53 89.92 90.32 90.71
615.75 621.26 626.79 632.35 637.94 643.54 649.18 654.83
37 V8 V4 3/a V2 5/8 3/4 \la
116.2 116.6 117.0 117.4 117.8 118.2 118.6 118.9
1075.2 1082.4 1089.7 1097.1 1104.4 1111.8 1119.2 1126.6
95.033 97.205 99.402 101.62 103.86 106.13 108.43 11 0.75
20 Va V4 3/8 V2 5/8 3/4 \la
62.83 63.22 63.61 64.01 64.40 64.79 65.18 65.58
314.16 318.09 322.06 326.05 330.06 334.10 338.16 342.25
29 Va V4 3/8 V2 5/8 3f4 \la
91.10 91 .49 91.89 92.23 92.67 93.06 93.46 93.85
660.52 666.22 671.95 677.71 683.49 689.29 695.12 700.98
38 Va V4 3/8 V2 5/a 3/4 \la
119.3 119.7 120.1 120.5 120.9 121.3 121.7 122.1
1134.1 1141.5 1149.0 1156.6 1164.1 1171.7 1179.3 1186.9
37.69 38.09 38.48 38.87 39.27 39.66 40.05 40.44
113.00 115.46 117.85 120.27 122.71 125.18 127.67 130.19
21 V8 V4 3/8 V2 5/8 3/4 \18
65.97 66.36 66.75 67.15 67.54 67.93 63.32 68.72
346.36 350.49 354.65 358.84 363.05 367.28 371 .54 375.82
30 V8 V4 3/a V2 5/a 3/4 7/a
94.24 94.64 95.03 95.42 95.81 96.21 96.60 96.99
706.86 712.76 718.69 724.64 730.61 736.61 742.64 748.69
39 V8 V4 3/8 V2 5/8 3/4 7/8
122.5 122.9 123.3 123.7 124.0 124.4 124.8 125.2
1194.5 1202.2 1209.9 1217.6 1225.4 1233.1 1240.9 1248.7
13 V8 V4 3/8 V2 5/8 3/4 \Is
40.84 41.23 41.62 42.01 42.41 42.80 43.19 43.58
132.73 135.29 137.88 140.50 143.13 145.80 148.48 151.20
22 Va V4 3/a V2 5/8 3/4 \la
69.11 69.50 69.90 70.29 70.68 71.07 71.47 71.86
380.13 384.46 388.82 393.20 397.60 402.03 406.49 410.97
31 V8 V4 3/a V2 5/8 3/4 \18
97.38 97.78 98.17 98.56 98.96 99.35 99.74 100.1
754.76 760.86 766.99 773.14 779.31 785.51 791.73 797.97
40 V8 V4 3/8 V2 5/8 3/4 \Is
125.6 126.0 126.4 126.8 127.2 127.6 128.0 128.4
1256.6 1264.5 1272.3 1280.3 1288.2 1291.2 1304.2 1312.2
19.635 20.629 21.647 22.690 23.758 24.850 25.967 27.108
14 V8 V4 3/8 V2 5/a 3f4 \la
43.98 44.37 44.76 45.16 45.55 45.94 46.33 46.73
153.92 156.69 159.48 162.29 165.13 167.98 170.87 173.78
23 V8 V4 3/8 V2 5/8 3/4 7/a
72.25 72.64 73.04 73.43 73.82 74.21 74.61 75.00
415.47 420.00 424.55 429.13 433.73 438.30 443.01 447.69
32 V8 V4 3/a V2 5/8 3/4 \/8
100.5 100.9 101.3 101.7 102.1 102.4 102.8 103.2
804.24 810.45 816.86 823.21 829.57 835.97 842.39 848.83
41 V8 V4 3/a V2 5/8 3/4 \la
128.8 129.1 129.5 129.9 130.3 130.7 131.1 131.5
1320.2 1328.3 1336.4 1344.5 1352.6 1360.8 1369.0 1377.2
18.84 19.24 19.63 20.02 20.42 20.81 21.20 21.57
28.274 29.464 30.679 31.919 33.183 34.471 35.784 37.122
15 V8 V4 3/S V2 5/a 3f4 \/a
47.12 47.51 47.90 48.30 48.69 49.08 49.48 49.87
176.71 179.67 182.72 185.66 188.69 191 .74 194.82 197.73
24 Va V4 3/8 V2 5/8 \Is
75.39 75.79 76.18 76.57 76.96 77.36 77.75 78.14
452.39 475.11 461.86 466.63 471.43 476.25 481.10 485.97
33 V8 V4 3/S V2 5/8 3f4 \Is
103.6 104.0 104.4 104.8 105.2 105.6 106.0 106.4
855.30 861.79 868.30 874.88 881.41 888.00 894.61 901.25
42 Vs V4 3/a V2 5/8 3/4 \Is
131.9 132.3 132.7 133.1 133.5 133.9 134.3 134.6
1385.4 1393.7 1401.9 1410.2 1418.6 1426.9 1435.3 1443.7
21.90 22.38 22.77 23.16 23.56 23.95 24.34 24.74
38.484 39.871 41.282 42.718 44.178 45.663 47.173 48.707
16 Vs V4 3fs V2 5/S 3f4 \18
50.26 50.65 51.05 51.44 51.83 52.22 52.62 53.01
201 .06 204.21 207.39 210.59 213.82 217.07 220.35 223.65
25 Vs V4 3/a V2 5/a 3f4 \18
78.54 78.93 79.32 79.71 80.10 80.50 80.89 81.28
490.87 495.79 500.74 505.71 510.70 515.72 520.70 525.83
34 Va V4 3/a V2 5/S 3f4 7/8
106.8 107.2 107.5 107.9 108.3 108.7 109.1 109.5
907.92 914.61 921 .32 928.06 934.82 941.60 948.41 955.25
43 Va V4 3/8 V2 5/8 3f4 7/8
135.0 135.4 135.8 136.2 136.6 137.0 137.4 137.8
1452.2 1460.6 1469.1 1477.6 1486.1 1494.7 1503.3 1511.9
3f4
43
CIRCUMFERENCES
44
AND AREAS Diam.
Cire.
Area
2206.1 2216.6 2227.0 2237.5 2248.0 2258.5 2269.0 2279.6
62 Va % 3/a V2 5/B 3/4 'l'a
194.7 195.1 195.5 195.9 196.3 196.7 197.1 197.5
169.6 170.0 170.4 170.8 171.2 171.6 172.0 172.3
2290.2 2300.8 2311.4 2322.1 2332.8 2343.5 2354.2 2365.0
63 VB % 3/B 112 5/a 3f4 'l'8
55 1Ia V4 3/8 VL 5/B 3f4 7/B
172.7 173.1 173.5 173.9 174.3 174.7 175.1 175.5
2375.8 2386.6 2397.4 2408.3 2419.2 2430.1 2441.0 2452.0
1734.9 1744.1 1753.4 1762.7 1772.0 1781.3 1790.7 1800.1
56 Va % 3/B 112 5/B 3/4 'l'B
175.9 176.3 176.7 177.1 177.5 177.8 178.2 178.6
150.7 151.1 151.5 151.9 152.3 152.7 153.1 153.5
1809.5 1818.9 1828.4 1837.9 1847.4 1856.9 1866.5 1876.1
57 VB V4 3/B 112 5fs 3f4 7/B
49 VB
153.9 154.3
1885.7 1895.3
% 3/B V2 5/B 3/4 7/B
154.7 155.1 155.5 155.9 156.2 156.6
50 Va V4 3/B V2 5/B 3/4 'l'a
OF CIRCLES
(CONT.)
Diam.
Cire.
Area
3019.0 3031.2 3043.4 3055.7 3067.9 3080.2 3092.5 3104.8
71 VB % 3/B V2 5/B 3/4 7/a
223.0 223.4 223.8 224.2 224.6 225.0 225.4 255.8
197.9 198.3 198.7 199.0 199.4 199.8 200.2 200.6
3117.2 3129.6 3.142.0 3144.4 3166.9 3179.4 3191.9 3204.4
72 Va % 3/a V2 5/a 3f4 7/B
64 Va % 3/B V2 5fs 3/4 7/B
201.0 201.4 201.8 202.2 202.6 203.0 203.4 203.8
3216.9 3229.5 3242.1 3254.8 3267.4 3280.1 3292.8 3305.5
2463.0 2474.0 2485.0 2496.1 2507.1 2518.2 2529.4 2540.5
65 1Ia % 3/B '/2 5/B 3/4 7/B
204.2 204.5 204.9 205.3 205.7 206.1 206.5 206.9
179.0 179.4 179.8 180.2 180.6 181.0 181.4 181.8
2551.7 2562.9 2574.1 2585.4 2596.7 2608.0 2619.3 2630.7
66 Va V4 3/B V2 5/B 3/4 7/B
58 Va
182.2 182.6
2642.0 2653.4
1905.0 1914.7 1924.4 1934.1 1943.9 1953.6
% 3/B V2 5/B 3f4 7/B
182.9 183.3 183.7 184.1 184.5 184.9
157.0 157.4 157.8 158.2 158.6 159.0 159.4 159.8
1963.5 1973.3 1983.1 1993.0 2002.9 2012.8 2022.8 2032.8
59 Va V4 3/B V2 5/B 3f4 7/a
51 VB
160.2 160.6
2042.8 2052.8
% 3/B '/2 5/B 3f4 7/B
161.0 161.3 161.7 162.1 162.5 162.9
52 Va % 3/B 112 5/8 3/4 'l'8
163.3 163.7 164.1 164.5 164.9 165.3 165.7 166.1
Diam.
-
Diam.
Cire.
Area
3959.2 2973.1 3987.1 4001.1 4015.1 4029.2 4043.2 4067.3
84 % V2 3/4
263.8 264.6 265.4 226.2
5541.7 5574.8 5607.9 5641.1
85 % V2 3f4
267.0 267.8 268.6 269.3
5674.5 5707.9 5741.4 5775.0
226.1 226.5 226.9 227.3 227.7 228.1 228.5 228.9
4071 .5 4085.6 4099.8 4114.0 4128.2 4142.5 4156.7 4171.0
86 % V2 3f4
270.1 270.9 271.7 272.5
5808.8 5842.6 5876.5 5910.5
87 % '/2 3/4
273.3 274.1 274.8 275.6
5944.6 5978.9 6013.2 6047.6
73 VB V4 3/B V2 5/a 3f4 7/a
229.3 229.7 230.1 230.5 230.9 231.3 231.6 232.0
4185.3 4199.7 4214.1 4228.5 4242.9 4257.3 4271.8 4286.3
88 % V2 3/4
276.4 277.2 278.0 278.8
6082.1 6116.7 6151.4 6186.2
89 V4 V2 3/4
279.6 280.3 281.1 281.9
622.11 6256.1 6291.2 6326.4
3318.3 3331.0 3343.8 3356.7 3369.5 3382.4 3395.3 3408.2
74 VB V4 3/B V2 5fs 3f4 'l'B
. 232.4 232.8 233.2 233.6 234.0 234.4 234.8 235.2
4300.8 4315.3 4329.9 4344.5 4359.1 4378.8 4388.4 4403.1
90 V4 V2 3/4
282.7 283.5 284.3 285.1
6361.7 6397.1 6432.6 6468.2
207.3 207.7 208.1 208.5 208.9 209.3 209.7 210.0
3421 .2 3434.1 3447.1 3460.1 3473.2 3486.3 3499.3 3512.5
75 V4 V2 3f4
235.6 236.4 237.1 237.9
4417.8 4447.3 4476.9 4506.6
91 V4 112 3/4
285.8 286.6 287.4 288.2
6503.8 6539.6 6575.5 6611.5
92 % '/2 3/4
289.0 289.8 290.5 291.3
6647.6 6683.8 6720.0 6756.4
76 V4 112 3/4
238.7 239.5 240.3 241.1
4536.4 4566.3 4596.3 4626.4
67 1IB
210.4 210.9
3525.6 3538.8
93 V4 112 3/4
292.1 292.9 293.7 294.5
6792.0 6829.4 6866.1 6902.9
2664.9 2676.3 2687.8 2690.3 2710.8 2722.4
% 3/B V2 5/B 3/4 7/B
211.2 211.6 212.0 212.4 212.8 213.2
3552.0 3565.2 3578.4 3591.7 3605.0 3618.3
77 % V2 3f4
241.9 242.6 243.4 244.2
4666.6 4686.9 4717.3 4747.7
94 % 112 3/4
295.3 296.0 296.8 297.6
6939.7 6976.7 7013.8 7050.9
185.3 185.7 186.1 186.5 186.9 187.3 187.7 188.1
2733.9 2745.5 2757.1 2768.8 2780.5 2792.2 2803.9 2815.6
68 Va % 3/B V2 5/B 3/4 'l'B
213.6 214.0 214.4 214.8 215.1 215.5 215.9 216.3
3631.6 3645.0 3658.4 3671.8 3685.2 3698.7 3712.2 3725.7
78 % V2
245.0 245.8 246.6
4778.3 4809.0 4839.8
95 % V2
298.4 299.2 300.0
7088.2 7125.5 7163.0
3/4
247.4
4870.7
3f4
300.8
7200.5
79 % V2 3/4
248.1 248.9 249.7 250.5
4901.6 4932.7 4963.9 4995.1
96 V4 V2 3f4
301.5 302.3 303.1 303.9
7238.2 7275.9 7313.8 7341.7
60 1IB
188.4 188.8
2827.4 2839.2
69 Va
216.7 217.1
3739.2 3752.8
80 % V2 3f4
251.3 252.1 252.8 253.6
5026.5 5058.0 5089.5 5121.2
97 V4 V2 3/4
304.7 305.5 306.3 307.0
2062.9 2072.9 2083.0 2093.2 2103.3 2113.5
% 3/B 112 5/B 3f4 7/B
189.2 189.6 190.0 190.4 190.8 191.2
2851.0 2862.8 2874.7 2886.6 2898.5 2910.5
V4 3/B 112 5fs 3/4 7/B
7389.8 7427.9 7466.2 7504.4
217.5 217.9 218.3 218.7 219.1 219.5
3766.4 3780.0 3793.6 3807.3 3821.0 3834.7
81 V4 112 3/4
254.4 255.2 256.0 256.8
5153.0 5184.8 5216.8 5248.8
98 % '/2 3/4
307.8 308.6 309.4 310.2
7542.9 7581.5 7620.1 7658.8
2123.7 2133.9 2144.1 2154.4 2164.7 2175.0 2185.4 2195.7
61 Va % 3/B 112 5/8 3f4 'l'a
191.6 192.0 192.4 192.8 193.2 193.6 193.9 194.3
2922.4 2934.4 2946.4 2958.5 2970.5 2982.6 2994.6 3006.9
70 V8 V4 3/B 112 5/8 3/4 'l'a
219.9 220.3 220.6 221.0 221 .4 221.8 222.2 222.6
3848.4 3862.2 3875.9 3889.8 3903.6 3917.4 3931.3 3945.2
82 V4 112 3f4
257.6 258.3 259.1 259.9
5281.0 5313.2 5345.6 5378.0
99 V4 V2 3/4
311.0 311.8 312.5 313.3
7697.7 7736.6 7775.6 7814.7
83 '/4 V2 3f4
260.7 261.5 262.3 263.1
5410.6 5443.2 5476.0 5508.8
100 % V2 3f4
314.1 314.9 315.7 316.4
7853.0 7893.3 7932.7 7972.2
Cire.
Area
Diam.
Cire.
Area
44 Va % 3/B '/2 5/a 3/4 7/B
138.2 138.6 139.0 139.4 139.8 140.1 140.5 140.9
1520.5 1529.1 1537.8 1546.5 1555.2 1564.0 1572.8 1581.6
53 1IB % 3/B V2 5/a 3f4 7/a
166.5 166.8 167.2 167.6 168.0 168.4 168.8 169.2
45 Va % 3/B 112 5/a 3f4 7/B
141.3 141.7 142.1 142.5 142.9 143.3 143.7 144.1
1590.4 1599.2 1608.1 1617.0 1625.9 1634.9 1643.8 1652.8
54 Va % 3/a V2 5/8 3f4 7/8
46 VB % 3/B V2 5/a 3/4 7/B
144.5 144.9 145.2 145.6 146.0 146.4 146.8 147.2
1661.9 1670.9 1680.0 1689.1 1698.2 1707.3 1716.5 1725.7
47 Va V4 3/B 112 5/a 3f4 7/B
147.6 148.0 148.4 148.8 149.2 149.6 150.0 150.4
48 VB % 3/B V2 5/B 3/4 7/B
'-'
/
...J
I
TORQUE REQUIRED TO PRODUCE BOLT STRESS
........
The torque or turning effort requiredto produce a certain stress in bolting is dependent upon a number of conditions, some of which are: 1. Diameter of bolt. 2. Type and number of threads on bolt. 3. Material of bolt. 4. Condition of nut bearing surfaces. 5. Lubrication of bolt threads and nut bearing surfaces.
The tables below reflect the results of many tests to determine the relation between torque and bolt stress. Values are based on steel bolting well lubricated with a heavy graphite and oil mixture. It was found that a non-lubricated bolt has an efficiency of about 50 percent of a well lubricated bolt and also that different lubricants produce results varying between the limits of 50 and 100 percent of the tabulated stress figures.
Data for Use with Machine Bolts and Cold Rolled Steel Stud Bolts
Load inPounds on Bolts and Stud Bolts wh~n Torque Loads Are Applied NOMINAL DIAMETER OF BOLT (Inches) %
(Per Inch) 20
(Inches)
5/16
18 16 14 13 12 11 10 9 8 7 7 6 6 5V2 5 5 4V2
.240 .294 .345 .400 .454 .507 .620 .731 .838 .939 1.064 1.158 1.283 1.389 1.490 1.615 1.711
3/8 7/16
V2 9/16
\...;
NUMBER DIAMETER AREA OF AT ROOT AT ROOT THREADS OF THREAD OF THREAD
5/8 3/4 \18 1 1V8 1% 13/8 1V2 1% 13/4 1\18 2
.185
ISo. Inch) .027
.045 .068 .093 .126 .162 .202 .302 .419 .551 .693 .890 1.054 1.294 1.515 1.744 2.049 2.300
7,500 PSI Torque Ft. Lbs. 1
2 3 5 8 12 15 25 40 62 98 137 183 219 300 390 525 563
Com pression, Lbs. 203
338 510 698 945 1215 1515 2265 3143 4133 5190 6675 7905 9705 11363 13080 15368 17250
STRESS 15,000 PSI Torque Ft. Lbs. 2
4 6 10 15 23 . 30 50 80 123 195 273 365 437 600 775 1050 1125
30,000 PSI
Compression, Lbs. 405
Torque Ft. Lbs.
675 1020 1395 1890 2430 3030 4530 6285 8265 10380 13350 15810 19410 22725 26160 30735 34500
8 12 20 30 45 60 100 160 245 390 545 730 875 1200 1550 2100 2250
4
Compression, Lbs. 810
1350 2040 2790 3780 4860 6060 9060 12570 16530 20760 26700 31620 38820 45450 52320 61470 69000
Data for Use with Alloy Steel Stud Bolts
Load inPounds on Stud Bolts when Torque Loads Are Applied NOMINAL DIAMETER OF STUD
STRESS 30,000 PSI Torque Ft. Lbs.
(Inches)
IPer Inch)
%
20
.185
.027
4
5/16
18 16 14 13 12 11 10 9 8 8 8 8 8 8 8 8 8 8 8 8 8
.240 .294 .345 .400 .454 .507 .620 .731 .838 .963 1.088 1.213 1.338 1.463 1.588 1.713 1.838 2.088 2.338 2.588 2.838
.045 .068 .093 .126 .162 .202 .302 .419 .551 .728 .929 1.155 1.405 1.680 1.980 2.304 2.652 3.423 4.292 5.259 6.324
8 12 20 30 45 60 100 160 245 355 500 680 800 1100 1500 2000 2200 3180 4400 5920 7720
3/8 7/16
V2 9/16
'-'"
NUMBER DIAMETER AREA OF AT ROOT AT ROOT THREADS OF THREAD OF THREAD
5/8 3/4 \18 1 1V8 1% 13/8 11/2 15/8 13/4 1\18 2 2% 2V2 23/4 3
(Inches)
ISa. Inch)
45,000 PSI
Compression, Lbs. 810
Torque Ft. Lbs.
1350 2040 2790 3780 4860 6060 9060 12570 16530 21840 27870 34650 42150 50400 59400 69120 79560 102690 128760 157770 189720
12 18 30 45 68 90 150 240 368 533 750 1020 1200 1650 2250 3000 3300 4770 6600 8880 11580
6
60,000 PSI
Compression, Lbs. 1215
Torque Ft. Lbs.
2025 3060 4185 5670 7290 9090 13590 18855 24795 32760 41805 51975 63225 75600 89100 103680 119340 154035 193140 236655 284580
16 24 40 60 90 120 200 320 490 710 1000 1360 1600 2200 3000 4000 4400 6360 8800 11 840 15440
8
Compression, Lbs. 1620
2700 4080 5580 7560 9720 12120 18120 25140 33060 43680 55740 69300 84300 100800 11 8800 138240 159120 205380 257520 315540 379440
45
Bolting Materials ASTM
A325
-
A354
BB BC
Notes
-20to 650
700
-
(1)
750
-
-
800
850
900
950
1000
1050
1100
-
-
-
-
-
-
-
-
-
-
-
BD
(2)(3) (2)(3) (2)(3) (2)(3)
18,750 18,750 20,000 20,000
17,200 17,200 18,400 18,400
15,650 15,650 16,750 16,750
B7 B5 B14 B16
(2)(3) (2)(3) (2)(3) (2)(3)
20,000 20,000
20,000 20,000
20,000 20,000
20,000 20,000
20,000 20,000
20,000 20,000
ASTM - A193 - Grade B6 B8 B8C B8T
Table 1
Maximum Allowable Stress Valus (psi) For Metal Temperatures Not Exceeding Deg. F
Specification Number Grade B A307
A193
Stress
* (UCS-, UHA-, UNF-23)
-
-
-
-
20,000 20,000 20,000 20,000
-
-
16,250 17,250 18,750 18,750
-
-
-
-
-
v
-
-
-
12,500 13,750
8,500 10,300
4,500 7,300
4,800
2,750
16,650 16,650
14,250 14,250
11,000 11,000
6,250 6,250
2,750 2,750
Maximum Allowable Stress Values (psi) For Metal Temperatures Not Exceeding Deg. F -. Notes
(2) (2)(4)(5) (2)(4)(5) (2)(4)(5)
B6
(2) B8 (2)(4)(5) B8C (2)(4)(5) B8T (2)(4)(5) ASTM A320 Grade L7, L9, L10 B8F
-20 to 100
200
300
400
500
600
650
700
750
800
850
900
20,000 15,000 15,000 15,000
19,300 13,300 15,000 15,000
18,700 12,000 13,600 13,600
18,300 10,900 12,650 12,650
17,850 10,000 12,200 12,200
17,000 9,300 11,900 11,900
16,500 8,950 11,850 11,850
15,750 8,650 11,800 11,800
14,900 8,300 11,750 11,750
13,800 8,000 11,650 11,650
12,500 7,750 11,450 11,450
11,000 7,500 11,300 11,300
950 -
1000 -
1050 -
1400
1450
1500
7,250 11,100 11,100
7,050 10,800 10,800
6,800 10,500 10,500
For Metal Temperatures Not Exceeding Deg. F 1100 1150 1200 1250 1300 1350 6,300 10,000 10,000
5,750 8,000 8,000
4,500 5,000 5,000
3,250 3,600 3,600
2,450 2,700 2,700
1,800 2,000 2,000
1,400 1,550 1,550
1,000 1,200 1,200
-
.-
750 1,000 1,000
Notes (2)(6) (2)(4)(7)
These materials are for low temperature service. Tensile range given in Materials Table 2 (page 6), is based on bolt diameter. Refer to ASTM Specification A320 for details. (1) Not permitted above 450F; allowable stress value 7,000 psi. (Table strength, or 25% of the specified yield strength. (Table UCS-23.) (4) These stress values permitted for material that has been carbideUCS-23.) solution treated. (Table UHA-23.) (2) These stress values are established from a consideration of (5) These stress values apply only when the carbon is 0.04% or strength only and will be satisfactory for average service. For higher. Table UHA-23.) bolted joints, where freedom from leakage over a long period of (6) For temperatures below 400F, stress values equal to 20% of time without retightening is required, lower stress values may be necessary as determined from the relative flexibility of the flange the specified minimum tensile strength will be permitted. (Table UCS-23.) and bolts, and corresponding relaxation properties. (Tables UCS-23 and UHA-23.) (7) For temperatures below 100F, stress values equal to 20% of (3) Between temperatures of - 20F to 400F, stress values equal to the the specified minimum tensile strength will be permitted. (Table UHA-23.) lower of the following will be permitted: 20% of the specified tensile
v
Note: *
It is often necessary to tighten bolting to much higher stresses than those given in the Table in order to prevent leakage under hydrotest and also to obviate frequent retightening due to relaxation. The Code does not prohibit this practice and the stress values listed are rather to be considered
as
applying in the design of flanges.
I
46
BOLTING DATA FOR STANDARD FLANGES 300 PSI SERIES
150 PSI SERIES
'-'
NOMINAL PIPE SIZE (Inches}
Dlam. of
c:w
%
331a
V2
3V2 3a 4% 4% 5 6 7 7% 8V2 9 10 11 13V2 16 19 21 23V2 25 27V2 32
3/4
1 W. W2 2 2V2 3 3V2 4 5 6 8 10 12 14 16 18 20 24
Dlam. of
Num-
':I: 4 4 4 4 4 4 4 4 4 8 8 8 8 8 12 12 12 16 16 20 20
(Ig':a}
V2 V2 V2 V2 % % 51a
% % 5/a 51a
3/4 3/4 3/4
7/a 7/a 1 1 1Va Wa 1%
Bolt
Dlam. of
Num-
(r}
(I)
Dlam. of
el:
2% 23/a 23/4 3Va 3% 3a
3% 33/4 4% 4a 5% 6Va 43/4 6V2 5V2 7V2 6 8% 7 9 7V2 10 8V2 11 9V2 12% 113/4 15 14% 17V2 17 20% 183/4 23 21% 25Y2 223/4 28 25 30% 29% 36
(Ig':a)
4 4 4 4 4 4 8 8 8 8 8 8 12 12 16 16 20 20 24 24 24
V2 V2 % 51a
% 3/4 5/a 3/4 3/4 3/4 3/4
3/4 3/4
a 1 Wa 1Va 1% 1% 1% 1V2
900 PSI SERIES
NOMINAL PIPE SIZE (Inches) Y2 3/4
\,.,.;
1 1% lV2 2 2V2 3 4 5 6 8 10 12 14 16 18 20 24
Dlam. of (r)
Number of Bolts
4314 5Va
4
5a 6% 7 8V2 9% 9V2 11V2 15 18V2 21Y2 24 25%
4 4 4 8 8 8 8 8 12 12 16 20 20
273/4 31 333/4 41
133/4
Dlam. of Bolts (Inches)
Bolt (ICircle Inches) 3% 3V2
a a
e We 1% 1Ve 13/e 1% 13/e 1Y2
4 43/a 4a 6V2 7% 7% 9% 11 12V2 15V2 18% 21 22
20
151a
20 20
Ha 2
20
2V2
1 a 1
Bolt
Num-
I (r}
(I}
Dlam. of
600 PSI SERIES
Bolt
I::Sf (Ig,:':a} (I}
4 4 4 4 4 4 8 8 8 8 8 8 12 12 16 16 20 20 24 24 24
2% 2% 3%
3% 33/4 40/a 3V2 4a 37/a 5% 4V2 6Va 5 6V2 7'/2 57/a 65/a 8% 7V4 9 77/a 10 9% 11 1051a 12V2 13 15 15% 17'/2 173/4 20V2 20% 23 22Y2 25V2 243/4 28 27 30V2 32 36
V2 V2 51a
% % 3/4 % 314 3/4
7/a 7/a 7/a 7/a 1 1Va 1% 1% Pia 1% 1V2 13/4
Dlam. of
Dlam. of Flange (Inches) 43/4 5Va 5'l'a
Number of Bolts. 4 4
10V2 12% 143/4 15V2 19 23 26V2 29V2
4 4 4 8 8 8 8 8 12 12 12 16 16
24%
32Y2
27 29V2 35Y2
Dlam. of Bolts (Inches) 3/4 3/4
a
Num-
r:)
2% 2% 3% 3V2 3a 4V2 5 5a 65/a 7% 7a 9% 105/a 13 15% 173/4 20% 22V2 243/4 27 32
I::Sf (Ig:S}
33/a 33/4 4% 47/a 5% 6Va 6V2 7V2 8% 9 103/4 13 14 16V2 20 22 233/4 27 29V4 32 37
4 4 4 4 4 4 8 8 8 8 8 8 12 12 16 20 20 20 20 24 24
Bolt Circle (Inches) 3% 3V2
4
Number of Bolts
4 4 4 4 4 8 8 8 8 8 8 12 12 12
1 1Ve 1% 1Y2
7V2 8 9V2 11V2
13/a
12V2
1% Ha 2 2%
15V2 19 22V2 25
16
2V2
273/4
....
.... ....
36
16
23/4
383/4 46
16
3
30V2 323/4
.... ....
16
3V2
39
....
951a
7/a
1 7/a
V2 V2 o/a 5/a 5/a 314 5/a 3/4
3/4 7/a 7/a 1 1 1Va 1% 1% 13/a 1V2 1% 15/a 17/a
Bolt (II
2% 2% 3% 3V2 3a 4V2 5 5a 60/a 7% 8% 10V2 1W2 133/4 17 19% 203/4 233/4 253/4 28V2 33
2500 PSI SERIES
Dlam. of Flange (Inches) 5% 5%
6% 7% 8 9% 10V2 12 14 16V2 19 213/4 26% 30 ....
6% 7 8V2
Dlam. of
-
1500 PSI SERIES
3/4 3/4
4
400 PSI SERIES
Dlam. of
43/a
4a 6V2
Dlam. of Bolts (Inches) 3/4 3/4
a 1 1Ve 1 1Ve 1% 1%
Bolt Circle (Inches) 3V2 33/4
4% 5Va 53/4 6314 73/4 9 103/4
13/4
123/4
2 2 2V2 23/4 ....
14Y2 17% 21% 24%
....
.... ....
.... ....
....
....
.....
....
....
""
....
'-'
47
